Part of Total hip replacement rehab
How to sleep after a hip replacement, and why you have read three different answers
Warning signs, and when to get help
How should you sleep after a hip replacement?
Start with the paperwork you came home with, because this is one of the few questions in this recovery where somebody has already written you a personal answer. What your hospital told you about how to sleep after your hip replacement outranks everything below, and if it says nothing, that silence is a question for your team rather than a gap for the internet to fill.
If you are reading this in the middle of the night because you have woken up in a position you were told to avoid, and you want to know whether it has done any harm, skip the rest of this and go to what to do if you wake up in a position you were told to avoid. The short version is there: come out of it slowly rather than jerking out of it, get onto your back or the side you are allowed, then check three things. What changes that answer is also there. Sudden severe pain in the hip or groin with a leg that will not move or take your weight, or a leg that now looks shorter or turned in or out, is an emergency, whatever time it is.
Why have you read three contradictory answers? Because the hospitals themselves differ, and that is what brings most people to a page like this at two in the morning. Five current sources, side by side.
- Leeds Teaching Hospitals asks its patients to sleep on their back for six weeks, and says the surgeon decides whether you need hip precautions at all.
- Gateshead Health gives three precautions for six weeks after surgery, and the second of them is not to move the leg across your midline, with no crossed legs and lying on your back in bed given as the examples. So back lying arrives there as part of a restriction rather than as a recommendation.
- Newcastle Hospitals names back lying with a pillow between the legs as the recommended position, then opens the unoperated side with a pillow between the legs and one behind the back, if your consultant agrees. It also says some people need to lie on their back for a period of four to six weeks, and puts its restrictions at 6 to 12 weeks depending on the consultant.
- Cambridge University Hospitals gives no list of hip precautions at all. It says many people favor lying on their back for a while, and that either side is open to you if it is comfortable, with a pillow between the legs if you are on the unoperated one.
- The NHS recovery page runs through crossed legs, bending, low chairs and low toilet seats, and never names a sleeping position anywhere.
Five respectable sources, five answers, all live today. That is not a mistake by one of them and it is not a sign that yours is out of date. Notice which way the spread runs, though, because it is not evenly balanced: two of the five ask for your back for six weeks, a third recommends your back and opens one side only with the consultant's agreement, and only the leaflet that gives no precautions at all leaves both sides open.
OrthoInfo explains the mechanism behind the spread. It says you may be asked to take special precautions for sitting, bending and sleeping, usually through the first 6 weeks, and that what you are asked depends on the route your surgeon took into the hip. In bed that matters more than anywhere else in the house. A sleeping position can bend the hip, carry the leg across the middle of your body, or turn it in or out, and those are the movements the lists are built around.
One thing about those three that the lists themselves rarely spell out. After a hip reached from the back, what takes a new hip to the edge of its socket is not any one of them on its own. It is the three arriving together: the hip bent, the leg carried across the midline, and the knee rolled inward. Bed is the one place in the house where that combination assembles itself without you doing anything. Lie on a side with nothing between your knees and the upper leg slides forward and down, which bends the hip, brings it across your body and turns it inward, all three at once, while you are asleep and cannot feel it happening. That is the single reason a pillow keeps appearing in these leaflets, and it is why a position that feels fine as you drift off is not the position you are in at four in the morning.
A hip reached from the back is usually guarded against deep bending, crossing and turning in. Reach it from the front and the caution tends to run the other way, against the leg traveling backward and turning out, and those two together more than either on its own.
An operation from the side of the hip raises both questions at once, and this is the one most people get wrong about themselves. In that route the front part of the muscles at the side of the hip (the abductors, gluteus medius and gluteus minimus) is lifted off the bony point at the top of the thigh (the greater trochanter) along with the front of the joint capsule, and all of it is stitched back through drill holes in that bone at the end of the operation (Agarwala and Jagani, 2018). So the front of the capsule is the part that was opened, which makes the leg traveling backward and turning outward the first thing to ask about, not the famous back-approach list. And the repair is the second thing, because it sits directly under the point your body weight rests on when you lie on that side.
So the approach decides the answer, and most people do not know theirs. If you do not know which approach was used, the leaflet you came home with, your discharge letter and the ward that looked after you can all tell you, and the scar on its own cannot, because a scar on the side of the hip can belong to more than one approach. The whole subject, including the lists themselves and how long they run, belongs to hip precautions after a hip replacement, and this page sends you there instead of printing a list of its own.
One last thing before the detail. Whatever you read here, the plan your surgeon and your hospital physio or physical therapist set for you comes first, and nothing on this page is a reason to set any part of it aside. Where the nights sit in the rest of the recovery is on the total hip replacement rehab program, which answers the sleep and night pain questions in short form. What a page can do is help you ask a better question at your follow-up.
Can you sleep on your side after a hip replacement?
Often yes, in time. Which side, and from when, is your team's call. The count above is the honest answer: two of the five sources allow a side, two ask for six weeks on your back, and one never raises the subject.
Where a side is allowed, the details are worth copying out of the leaflet. Newcastle pairs the unoperated side with a pillow between the legs and a second pillow behind your back, and makes the permission conditional on your consultant. A conditional permission is as clear a sign as you will find that this is a local decision and not a rule of the operation. It also adds a point nobody else does: while you are lying on your side, keep the hip from bending past a right angle, which it gives as 90 degrees. Cambridge, giving no precautions, simply treats comfort as the test.
Until your own team tells you, the cautious set is the one written for a hip reached from the back: your back or the unoperated side, nothing crossing the middle of your body, and no twisting on the new leg. None of those is a problem after a front approach either, so it is the safe default while you are waiting to be told, and it is not a substitute for being told.
What that set leaves out, in bed specifically, is the opposite direction, and bed is where the opposite direction happens. So add two things to it while you are waiting: do not sleep on your front, which takes the hip to its straightest and usually turns the leg outward, and do not take the operated side until somebody has told you it is allowed. Both of those are free to give up for a few nights, and both are positions a front or a side approach may restrict while the back-approach list says nothing about them at all.
If you are pregnant, this is the one place on the page where two sets of advice pull against each other, and it needs both of your teams rather than a decision made in bed at night. From about 28 weeks of pregnancy the NHS advises going to sleep on your side rather than on your back, because it says sleeping on your back after that point can double the risk of stillbirth. So use the unoperated side, with a pillow between your legs, and leave lying on your back until after the birth. The NHS also says not to worry if you wake up on your back: settle onto your side again and carry on. If you are pregnant and recovering from a hip replacement, put that overlap to your surgical team and your midwife together, because a protocol asking for back lying and the pregnancy advice point different ways and the two of them need to resolve it, not you. Say in plain words that you were told to lie on your back after your hip operation, because that is the detail that makes it their decision rather than a general question about sleep, and ask this week rather than at the next routine appointment.
Sleeping positions after a hip replacement: the operated side and the other one
The words themselves trip people up, so plainly: the operated side is the hip that was replaced. Lying on your operated side puts that hip, its wound and its swelling against the mattress, with the weight of your upper body on top. Lying on your other side, which people call the good side even when it is arthritic, leaves the new hip uppermost, and it is then free to drop inward across your body unless something holds it apart.
That is why the hospitals that open a side open the unoperated one, and why a pillow usually comes with the permission.
You came here for a number. Not one of the sources read for this page gives a number of weeks before you may lie on the operated side, so neither does this page, and be wary of any page that does. The decision belongs to the team who operated, for reasons specific to you: how the wound and the swelling are settling, which approach was used and therefore which direction the hip is least steady in, and whether anything was repaired that your own weight would press on. After an operation through the side of the hip, that last one is a surgeon's judgment and not a comfort question.
It is worth knowing what reason a surgeon is actually weighing there, because then you can ask for the reason rather than for a week number. After a hip reached from the back, lying on that side is not the direction such a hip comes out in, so the answer turns on the wound, the swelling and the bruising over a joint that was opened days ago rather than on the socket. After a side approach it turns on a repair instead. Your weight presses straight down onto the greater trochanter, which is the bone the front of the abductors and the front of the capsule were stitched back onto through drill holes in it (Agarwala and Jagani, 2018). Tendon healing back onto bone is slow, and nobody times it by how the hip feels at bedtime. We found no published date for when that repair may be loaded, which is the honest reason this is a question for your team rather than a rule on a page, and if a crack or a cut through that bone was part of your operation then the timetable is the bone's and only your surgeon has it.
There is a second reason the operated side is a bigger decision than it looks, and it has nothing to do with the first night. Most people do not stay square on a side once they are asleep: they roll part way onto the front, which takes the hip backward and turns the leg outward. So when you ask about the operated side you are asking about that position too, not only about the tidy one you fall asleep in.
So, practically: ask at your next contact, push for a date instead of a vague answer, and write it down. Ask the same question about the pillow at the same time, so you are not left guessing about one half of the set-up.
If the reason you want the operated side is that your other hip is the arthritic one and lying on it hurts, say exactly that when you ask, because it changes the conversation. Sleeping with an arthritic hip is a different subject with its own answers, and sleeping positions and night pain with hip arthritis covers it, with the caution that its advice is written for a hip that has not been operated on.
Pillows: between the legs, under the knees, and the wedge
The pillow between the legs does two completely different jobs depending on who gave it to you, and knowing which one yours is doing is the whole point of this section.
In Newcastle's instructions it is structural. It travels with the hip restrictions, it holds the leg away from the middle of your body, and it ends when the restrictions end, which that hospital puts at 6 to 12 weeks depending on the consultant. What it is doing while you sleep is blocking two movements rather than one. The upper knee cannot travel across the midline, and because it cannot slide forward past the pillow either, the leg cannot roll inward at the same time. Those two together with a bent hip are the combination described further up this page, which is the reason a pillow is part of a restriction at all rather than a kindness. In the Cambridge leaflet it is comfort, offered for the unoperated side, with no list around it and no end date. Dropping a comfort measure costs you a worse night. Dropping a restriction is a different matter, which is why the question to ask is not how long but which kind.
If you are using one, the thing that decides whether it works is whether it is still filling the gap at four in the morning. A thin pillow flattens, the upper leg slides down the slope of it, and the leg finishes in the position the pillow was there to prevent. A folded standard pillow is usually enough, and there is nothing here that needs buying.
A pillow under the knees is a separate decision and worth one caution. It is a reasonable comfort measure, but it parks the hip in a slightly bent position for the whole night, and some teams want the opposite. Cambridge, for instance, asks its readers to lie flat for half an hour twice a day, to stretch the hip and restore good posture. Do that on your bed rather than down on the floor, unless somebody has shown you how to get down and up again safely, because getting off a floor is deep hip bending and the hardest transfer in the house. So if you are propping your knees every night, mention it. A pillow is not automatically neutral.
The wedge comes up constantly, usually from someone who has been given one and wants to know when they can stop. Nothing in the NHS recovery page, the OrthoInfo guide or the Leeds, Gateshead, Newcastle and Cambridge leaflets calls for a wedge pillow at home, and this page recommends no product of any kind. If your team supplied one and asked you to use it, keep to that and raise it with them, not here. And if you are using a wedge to prop your upper body instead of separating your legs, flag it when you ask. Sleeping on a slope closes the angle at the hip more than lying flat does, which makes it a precautions question.
Can you sleep on your front?
None of the six sources read for this page names lying on your front as a sleeping position, in either direction. That is useful information and not a dead end: it tells you front lying is not a standard sleeping instruction anywhere, so a confident answer online is somebody's opinion. One thing to be clear about, since you will find it if you go looking: the Cambridge leaflet, the one that gives no hip precautions, does use front lying for an exercise, and it sits in the advanced set that leaflet opens at six weeks, not in the early one. That is an exercise position in a program with no restrictions attached, not a sleeping permission, and it says nothing about a night on your front if you were given precautions.
Worth putting to your surgeon by name instead of trying it out. Lying on your front takes the hip toward its straightest position and usually turns the leg outward, and that combination is the one some teams are careful about after an operation from the front of the hip, or from the side of it, where the front of the capsule was opened and stitched back as well. Leg behind you and foot turned out is one position, not two, which is why it is worth more care than either half of it would suggest. It also presses directly on a healing wound, and in the early weeks that is usually what stops people before anything else does. Until you know which approach was used and what your own team restricts, treat the front as off the list rather than as untested.
The things-to-avoid question is bigger than the bed, and what to avoid after a hip replacement works through the rest of it.
Getting in and out of bed without twisting
This is the part of the night that actually causes trouble, and the Leeds leaflet is the only one of the four with specific instructions, so they are worth having. It says to get in and out on the side you normally use at home, not to let the operated leg cross the midline of your body while you do it, to roll the bedding aside before you get in, and that the bed should be a height that lets you keep your precautions.
That last point does more work than it looks. A bed you drop into and have to climb out of makes every other rule harder to keep, and it is usually fixable in an afternoon.
You were probably shown a method in hospital, and that version beats any written description, including this one. NICE recommends that rehabilitation after joint replacement starts on the day of surgery where that is possible, and within 24 hours otherwise. Bed transfers are one of the first things taught for that reason. If you have forgotten it, ask for it again. NICE also asks that people doing their own rehabilitation at home are given clear goals and a named person to contact, so there should be somebody to ask.
The general method of rolling and sitting up does not change much whatever the hip has been through, and the hip arthritis sleeping and night pain page sets out that sequence step by step. Read it knowing that it is written for a hip that has not been operated on, so the method you were shown in hospital and your own precautions come first wherever the two differ. What changes after surgery is the twisting. Come out of the bed as one piece, with your knees traveling together, rather than letting the top leg swing across first and the body follow.
The trip to the bathroom at 3am is where falls happen. OrthoInfo warns that a fall in the first few weeks after surgery can damage the new hip and may result in a need for more surgery, and calls stairs a particular hazard until the hip is strong and mobile. It asks you to use a cane, crutches, a walker or handrails, or to have someone help you, until your balance, flexibility and strength have improved, and to take loose carpets and electrical cords out of the places you walk and put handrails on the stairways. Do that in daylight.
Keep your walking frame or walker, or your stick or cane, within reach of the edge of the bed rather than across the room, and keep using it for as long as your physio asks rather than for as long as you feel wobbly. Balance and falls prevention covers the rest of it.
Why the new hip aches at night, and what helps
Partly because it is early. OrthoInfo describes discomfort at night, as well as with activity, as common for several weeks, Gateshead Health calls increased discomfort at night and difficulty sleeping very common after a hip replacement and expects it to improve with time, and the NHS says the pain and swelling in the leg and foot usually get better over a few weeks. An aching hip at night in the first weeks is the expected course, not a sign you have done something wrong in bed. What to expect week by week sets out the rest of that shape.
Sleep itself is also disrupted after a joint replacement for a lot of people, and the research says so plainly. A clinical review of sleep disorders after hip and knee replacement describes them as common, names pain, pain medicines, the stress of surgery and anxiety among the contributors, and reports no agreed best way to treat them (Purcell and colleagues, 2023). In a small study that followed 25 people having a hip replacement with a short-stem implant, sleep quality was no better in the first week after the operation and then improved steadily over six months, while daytime sleepiness improved at every check (Hochreiter and colleagues, 2020). Twenty-five people and one implant design is a narrow base, so read it for the shape rather than the numbers, and the shape is this: the first week is not a forecast.
The part that surprises people is that the problem often predates the operation. In 52 people assessed before hip replacement surgery, 73.1% had disturbed sleep on a standard questionnaire (Bjurstrom and colleagues, 2021). A hip bad enough to be replaced has usually been ruining nights for a year or more, which is one of the reasons it gets replaced. Why a hip replacement is needed covers that threshold.
What helps, in the order we would try it in clinic. Keep the leg moving during the day instead of sitting still for hours, since OrthoInfo lists ankle pump exercises and early movement among the ways the clot risk is managed, and a leg that has done nothing all day is stiffer at midnight. Ankle pumps are also something to do when you are awake at 3am and want to feel useful. Heel slides only within the limit your team set, since they bend the hip. Both give their own numbers on their pages, and your physio will adjust this.
Pain relief and its timing is a conversation for your surgical team, your doctor or a pharmacist, because the timing of a dose relative to bedtime is exactly the sort of thing they can adjust. Never stop or change a prescribed medicine on your own.
What to do if you wake up in a position you were told to avoid
This happens to almost everyone who is given a sleeping restriction, and the fear of it keeps people awake more effectively than the hip does. So, what to do.
Come out of the position slowly. Do not jerk out of it in fright. Get onto your back or onto the allowed side, and then check three things: whether the hip feels the way it did when you went to bed, whether the leg looks the same length and sits at the same angle as before, and whether you can stand and walk the way you could yesterday. If all three are unchanged, there is nothing there to suggest any harm has been done. Mention it at your next contact with the team and go back to sleep.
Testing it again to see whether it still feels odd is the one thing to leave alone.
What changes that answer is in the warning list at the foot of this page, and three lines matter most here. Sudden severe pain in the hip or groin, with or without a clunk, a leg that will not take weight, or a leg that now looks shorter or turned, is an emergency. A hip that clunked and felt as though it slipped and went back needs your surgical team the same day even if it settled instantly and the leg looks normal. And a pop or a sudden tearing pain over the side of the hip, after which the leg will not lift out to the side or will not hold you up as you stand, is the third, because muscle and tendon were stitched back during the operation and a repair that has let go is assessed rather than exercised. People do that one getting out of bed rather than in it. The reason the lists exist at all is that window: OrthoInfo puts the greatest dislocation risk in the first few months, while the tissues around the joint are healing. Greatest is not the same as only, and the NHS says a hip replacement can dislocate soon after surgery and also many years later, so the two lines above stay worth recognizing long after you have stopped thinking about how you sleep. Warning signs after a hip replacement goes through the whole set.
If you keep waking up in the wrong position, that is a problem to hand over rather than to fight alone. A second pillow lengthways behind your back is the simple version, and it is what Newcastle pairs with side lying. Beyond that, tell your team that you cannot hold the position they asked for, because that is a solvable rehabilitation problem and they would rather hear it early. NICE recommends supervised rehabilitation, in a group or one to one, for people who are having difficulty with daily activities or are not meeting their goals on their own. Sleeping and getting out of bed are daily activities.
When night pain means something else
Most night pain in the first weeks is the operation settling, and it eases. A few patterns are not that, and they are the ones to act on instead of rearranging pillows around them.
Pain that is climbing week by week instead of easing. Pain that builds at rest as much as it does on movement, which is one of the things OrthoInfo lists among the signs of infection, along with fever, chills, and a wound that is increasingly red, tender or swollen or starting to drain. Rest pain counts on its own, without any of the others for company. A normal temperature is not an all clear either: OrthoInfo's page on infection after a joint replacement says fever is no longer considered a sign of an infection after a joint replacement, and that the signs can be as little as mild redness and swelling. New pain in the hip months or years later, with or without a temperature, which has its own routine and same-day routes in the list below.
Three more have nothing to do with how you were lying. A calf or thigh that is newly swollen, warm or tender needs advice the same day, and lying still for long stretches is one half of why that risk exists after this operation. Sudden breathlessness or chest pain in the night is an emergency call even when the leg looks normal. And waking up more tired, more breathless or paler week by week, rather than less, is on the list below too, because blood loss around surgery can show up that way.
If the pain is coming from somewhere other than the new joint, hip pain at night works through the other causes.
If you cannot tell which of these you are looking at in the middle of the night, make the call in the morning rather than waiting for the follow-up. Your surgical team would much rather hear about a clunk that turned out to be nothing.
Related exercise programs
Warning signs
Get emergency help now
- Emergency: sudden severe pain in your hip or groin, sometimes with a clunk or pop, and you cannot move the leg or put weight on it, or the leg suddenly looks shorter or turned in or out. Do not try to walk on it or push it back into place. Keep still and call emergency services or go to an emergency department, and do not drive yourself. Your new hip may have come out of its socket (dislocated), and a medical team needs to put it back.
- Emergency: your operated leg looks shorter than it did, or its foot turns in or out more than before, or the hip moves in an unusual way, even if the pain is not severe. Keep your weight off it and go to an emergency department straight away, and do not drive yourself. If you are in severe pain or cannot move the leg, call emergency services.
- Emergency: you have just fallen and cannot get up, or you think you may have hurt your head, neck, back or hip. Stay where you are, keep warm and call emergency services, or get someone to call for you. If you got up and walked without trouble and only notice pain later, use the same-day lines in this list instead.
- Emergency: you have had a fall or an injury and now have severe hip pain, or you cannot walk or put weight on the leg. Call emergency services or go to an emergency department. This can be a sign of a broken hip (hip fracture).
- Emergency: since your operation, you suddenly become short of breath, you get chest pain or pain in your upper back that may be worse when you breathe in, you cough up blood, your heart is beating very fast, or you faint. Call emergency services straight away, even if your leg looks normal. These can be signs of a blood clot in the lungs (pulmonary embolism).
Get help today
- Same day: after a fall or a knock, even a small one, your hip, groin or thigh is newly painful, bruised or swollen, even if you can still walk and your leg looks normal. Stop the exercises, go back to your crutches or frame and keep your full weight off that leg, and contact your surgical team or get medical advice the same day. A break in the bone around a new hip is not always obvious at first, and walking normally on one can move the broken ends apart.
- Same day: a calf or thigh that is newly swollen or getting more swollen, warm, tender, red or darker than usual, has swollen veins that are sore to touch, or has a throbbing or cramping pain that does not fit your injury or condition, or that feels different from normal muscle soreness after exercise. This can be a sign of a blood clot (deep vein thrombosis), especially after surgery, an injury, time in a cast or boot, a long trip or a spell of being much less mobile than usual. Get medical advice the same day. If you are also short of breath or have chest pain, call emergency services.
- Same day: you are taking tablets or having injections to lower your risk of a blood clot and you notice blood in your urine, black or bloody stools, bleeding gums, a nosebleed that goes on and on, bruising far beyond what the knock would explain, or you are being sick or coughing up blood. Get medical advice the same day, and do not stop the medicine on your own. Bleeding more easily is the known trade-off of these medicines (NHS), and the dose or the type may need looking at. Go to an emergency department if the bleeding will not stop, you feel faint, or you bang your head while you are taking it, even if you feel fine, because the NHS advises getting urgent advice after a head injury on medicine that thins your blood and only a hospital can scan for a bleed inside the head.
- Same day: your wound becomes more red, hot, swollen or painful, starts to leak or ooze, is still leaking in the second week or has never stopped, has pus coming out of it or its edges start to come apart, or you have a high temperature or feel hot, cold or shivery. Contact your surgical team or get medical advice the same day. Redness can be harder to see on brown or black skin. If you feel very unwell, go to an emergency department. If you have a very high or very low temperature, shivering you cannot control, you are breathing very fast or finding it hard to breathe, you are confused or your speech is slurred, your skin, lips or tongue look blue, gray, pale or blotchy (on brown or black skin this can be easier to see on the palms of the hands or soles of the feet), or you have a rash that does not fade when you press it, call emergency services, as this can be sepsis.
- Same day: in the days or weeks after your operation you are getting more and more tired, breathless doing everyday things such as walking to the toilet or getting dressed, dizzy or lightheaded, your heart is racing, or your skin looks paler than usual. Contact your surgical team or get medical advice the same day. Tiredness and breathlessness that build up like this are not part of the usual recovery. Blood loss during and after a hip replacement can leave you short of red blood cells (anemia), which is treatable, and a slow bleed or an infection can show up the same way. If breathlessness comes on suddenly, or you get chest pain, call emergency services, as the emergency line above explains.
- Same day: dizziness, lightheadedness, blurred vision or feeling faint when you stand up that is new for you, does not pass within a minute or two, keeps happening, or has made you fall. Sit or lie down, and get medical advice the same day. This can be a drop in blood pressure on standing (postural hypotension), a type of low blood pressure, which the NHS lists among the causes of falls, and your doctor can check it. Tell them about your medicines, because some can cause it. If it does not settle within a few minutes of sitting or lying still, call emergency services. If you faint, call emergency services, even if you come round quickly, because the NHS says to call them when someone faints while exercising or is badly hurt, and a faint onto a new hip can dislocate it or break the bone around it.
- Same day: dizziness or feeling faint during or after exercise, other than the brief lightheadedness as you stand up covered in the line above, without any of the emergency signs above. Stop the exercises and get medical advice the same day. If you faint, it does not settle within a few minutes of sitting still, or you cannot stand or walk steadily, call emergency services.
- Same day: since your operation, the pain, redness, warmth, tenderness or swelling in your hip or leg is not getting better or is getting worse, for example the hip pain keeps building both when you move and when you rest, or you have a new throbbing or cramping pain in your hip or leg. Contact your surgical team or get medical advice the same day, as this can be a sign of infection around the new joint or a blood clot. If you feel very unwell, go to an emergency department.
- Same day: at any time after your operation, even years later, new pain in your new hip along with a high temperature or feeling hot, cold or shivery, or a hip that becomes hot, red or swollen, which counts on its own, with or without pain and with or without a temperature. Contact your surgical team or get medical advice the same day. A new joint can become infected long after the operation, and that needs treating quickly. A normal temperature is not an all clear: OrthoInfo says fever is no longer considered a sign of an infection after a joint replacement, that the signs can be as little as mild redness and swelling and sometimes there are none at all, and that increased pain or stiffness in a joint that had been working well is one of them. So do not wait for a temperature before you report new or increasing pain in your new hip to your surgical team.
- Same day: your hip clunks and feels as if it partly slipped out of place and went back, even if it settles straight away and your leg looks normal. Stop the exercises, avoid the movement that brought it on, go back to your crutches or frame, and keep away from deep bending, crossing your legs and twisting on that leg until you have been seen. Contact your surgical team or get medical advice the same day. If the leg then looks shorter or turned, or you cannot move it or put weight on it, call emergency services.
- Same day: you felt a pop, a snap or a sudden tearing pain over the side or the back of your hip, or your hip will not lift the leg out to the side any more, or it will not hold you up when you stand on that leg, so your hip drops or you lurch to one side. Stop the exercises, go back to your crutches or frame, and contact your surgical team or get medical advice the same day. Muscle and tendon are cut and stitched back during a hip replacement, and a repair that has given way needs assessing rather than exercising. If you cannot put weight on the leg at all, or the leg looks shorter or turned, call emergency services.
- Same day: a leg or foot that is getting weaker, for example your foot drags, catches on the ground or slaps down when you walk (foot drop). Get medical advice the same day. If the weakness is getting worse by the hour, go to an emergency department.
- Same day: new numbness, tingling or burning in your operated leg or foot, beyond the numb patch of skin around your scar. Contact your surgical team or get medical advice the same day. If it started after a fall or an injury, or your foot or toes turn cold, pale, blue or gray, call emergency services or go to an emergency department straight away, and do not drive yourself.
Book an appointment
- Within a few days: you have had a fall, even if you were not hurt, or you keep tripping, stumbling or feeling that your legs might give way. Book an appointment with your doctor within a few days and ask about a falls assessment. Tell them about every fall, even the ones where you were not hurt.
- Routine: since the operation your leg has felt a little longer or shorter than the other one, with no sudden change and no new pain. This is not unusual after a hip replacement. Mention it to your physio or at your follow-up appointment, as some people are more comfortable with a shoe raise.
- Routine: pain in your new hip that had settled and has come back, or pain that is getting worse month by month, for example in the groin or thigh when you first stand up and start to walk. This is not an emergency, but ask your surgical team for a review, as the parts of a new joint can loosen or wear over the years. Get medical advice the same day instead, not a routine appointment, if the hip also becomes hot, red or swollen, or you have a high temperature or feel hot, cold or shivery, or the pain is building week by week rather than month by month. A new joint can become infected years after the operation, and the two can feel similar at first.
Common questions
Can I sleep on my side after a hip replacement?
That depends on which hospital looked after you, and it is worth checking rather than guessing. Newcastle Hospitals allows the unoperated side with a pillow between the legs and another behind the back, says it depends on your consultant, and asks you to keep the hip from bending past a right angle while you are there. Cambridge University Hospitals leaves either side open if it is comfortable. Leeds Teaching Hospitals asks for six weeks on your back, and Gateshead Health puts lying on your back in bed inside its own six week precautions. All four are current, so the answer is in your own paperwork or a phone call, not in a general rule, and the published spread leans toward your back in the first six weeks.
Can I sleep on the side that was operated on?
Ask, and expect a cautious answer early on. Of the sources read for this page, only the Cambridge University Hospitals leaflet opens both sides, and it is the one that gives no hip precautions at all. Every hospital here that allows a side while restrictions are running names the unoperated one. None of them gives a week number for the operated side, so this page does not either. Two practical things push the same way: the wound and the swelling sit exactly where your weight would land, and after an operation done from the side of the hip the muscles there were stitched back onto the bony point at the top of the thigh that takes your weight in that position, which is a question for the surgeon rather than for comfort. Until you have asked, use your back or the unoperated side.
What is the best position to sleep in after a hip replacement?
The best position is the one your team allows that you can actually fall asleep in. For a lot of people in the first weeks that is on the back, which is what Newcastle recommends and what both Leeds and Gateshead require for six weeks, with a pillow between the legs if you were asked to use one. If you were given no precautions, as Cambridge gives none, then comfort decides and there is no position you have to train yourself into. Judge any set-up on how the hip feels when you first stand up, not on how virtuous it felt at bedtime.
Do I need a pillow between my legs, and for how long?
It has two different jobs, and which one yours is doing changes the answer. In Newcastle's instructions the pillow is part of the recommended position and sits with the rest of the hip restrictions, which that hospital puts at 6 to 12 weeks depending on the consultant. In the Cambridge leaflet it is offered for comfort on the unoperated side, with no precautions around it and no end date. So ask your own team whether yours is a restriction or a comfort measure, because only one of those matters if you drop it.
Do I need a wedge pillow?
Nothing in the NHS recovery page, the OrthoInfo guide or the Leeds, Gateshead, Newcastle and Cambridge leaflets asks for a wedge pillow at home, and this page does not recommend one or any other product. If your team gave you a wedge or any other pillow and told you to use it, that instruction is theirs and nothing here cancels it, so take it back to them rather than to a web page. One thing to raise if you are propping yourself up: sleeping with your upper body on a slope closes the angle at the hip more than lying flat does, which turns it into a precautions question rather than a furniture question.
Can I sleep on my stomach?
None of the six sources read for this page names lying on your front as a sleeping position, either to allow it or to rule it out, which is a fair sign of how rarely it comes up in the first weeks. Lying on your front straightens the hip and usually turns the leg outward, and that is the direction some teams are careful about after an operation done from the front of the hip, or from the side of it, so it is one to put to your surgeon by name rather than to try. The wound is the other reason most people do not try it early.
Why does my new hip ache at night?
Early on, because it is normal. OrthoInfo counts discomfort at night among the things that are common for several weeks after this operation, and the NHS expects the soreness and swelling in the leg and foot to ease over the first few weeks. Poor sleep after a joint replacement is common enough to have its own clinical review literature, with pain, pain medicines and anxiety all named among the causes (Purcell and colleagues, 2023). What does not fit that pattern is night pain that climbs week by week, pain that builds at rest as much as on movement, or night pain with a fever or a hot, swollen hip, and those need your surgical team the same day.
References
- NHS. Recovering from a hip replacement. Page last reviewed 6 March 2024. https://www.nhs.uk/tests-and-treatments/hip-replacement/recovering-from-a-hip-replacement/
- NHS. Complications of a hip replacement. Page last reviewed 6 March 2024. https://www.nhs.uk/tests-and-treatments/hip-replacement/complications-of-a-hip-replacement/
- NHS. Falls. https://www.nhs.uk/conditions/falls/
- NHS. Low blood pressure (hypotension). Page last reviewed 11 July 2023. https://www.nhs.uk/conditions/low-blood-pressure-hypotension/
- NHS. Fainting. https://www.nhs.uk/symptoms/fainting/
- NHS. 27 weeks pregnant: the best sleeping positions during pregnancy. Best Start in Life week by week guide. https://www.nhs.uk/best-start-in-life/pregnancy/week-by-week-guide-to-pregnancy/2nd-trimester/week-27/
- American Academy of Orthopaedic Surgeons. Total hip replacement. OrthoInfo. https://www.orthoinfo.org/en/treatment/total-hip-replacement/
- American Academy of Orthopaedic Surgeons. Infection after joint replacement. OrthoInfo. https://www.orthoinfo.org/en/diseases--conditions/joint-replacement-infection/
- Leeds Teaching Hospitals NHS Trust. Total hip replacement: a guide to your rehabilitation. Patient information. https://www.leedsth.nhs.uk/patients/resources/total-hip-replacement-a-guide-to-your-rehabilitation/
- The Newcastle upon Tyne Hospitals NHS Foundation Trust. Total hip replacement. Patient information. https://www.newcastle-hospitals.nhs.uk/resources/total-hip-replacement/
- Cambridge University Hospitals NHS Foundation Trust. Hip replacement, total: advice and exercises following. Patient information. https://www.cuh.nhs.uk/patient-information/hip-replacement-total-advice-and-exercises-following/
- Gateshead Health NHS Foundation Trust. Physiotherapy following hip replacement surgery. Patient information. https://www.gatesheadhealth.nhs.uk/resources/physiotherapy-following-hip-replacement-surgery/
- National Institute for Health and Care Excellence. Joint replacement (primary): hip, knee and shoulder. NICE guideline NG157. Published 4 June 2020. https://www.nice.org.uk/guidance/ng157
- Agarwala S, Jagani N. Osteotendinous suturing for anchorage of hip abductor mechanism in total hip arthroplasty through a lateral approach: a technical note. Journal of Orthopaedic Case Reports. 2018;8(2):26-29. https://pubmed.ncbi.nlm.nih.gov/30167407/
- Purcell KF, Scarcella N, Chun D, et al. Treating sleep disorders after total hip and total knee arthroplasty. Orthopedic Clinics of North America. 2023;54(4):397-405. https://doi.org/10.1016/j.ocl.2023.05.008
- Hochreiter J, Kindermann H, Mattiassich G, Ortmaier R, Mitterer M. Sleep improvement after hip arthroplasty: a study on short-stem prosthesis. International Orthopaedics. 2020;44(1):69-73. https://doi.org/10.1007/s00264-019-04375-1
- Bjurstrom MF, Irwin MR, Bodelsson M, et al. Preoperative sleep quality and adverse pain outcomes after total hip arthroplasty. European Journal of Pain. 2021;25(7):1482-1492. https://doi.org/10.1002/ejp.1761
Written and checked by the PocketPhysio editorial team. Last updated 2026-10-17.
This page is general education, not a diagnosis or a personal treatment plan. See a physiotherapist or doctor for advice about your own situation.