Hip Pain When Sleeping on Your Side: Why It Happens and How to Fix It

You fall asleep comfortably enough, then somewhere around 2am a deep, dull ache starts in the hip you are lying on. You shift to the other side, and an hour later that one is complaining too. By morning you feel like you have slept on a pavement, and the first few steps to the bathroom are stiff. Hip pain when sleeping on your side is one of the most common night-time complaints we hear about, and it catches people out because the hip usually feels fine during the day.

So what is actually hurting, why does it only flare up in bed, and what can you change tonight to get through to morning without the ache? This article explains the four most common causes, helps you work out which is yours, and takes you through the fixes in the order worth trying them.

Why does my hip hurt when I sleep on my side?

Those three mechanical causes account for most people. But an aching hip can also be the first sign of something in the joint itself, such as early osteoarthritis, or of a bursitis that has developed on the outside of the hip. Those need a different approach, so it helps to know the pattern of your own pain before you start buying things.

Cause 1: Pressure on the outside of the hip

The bony point of the hip was never designed to carry your weight for eight hours. On your side, the greater trochanter, the knob you can feel on the outside of the hip, presses into the mattress with much of your body weight on top of it. The tendons and fluid-filled cushions (bursae) that sit over that bone get compressed. Do that every night and they become inflamed, which is why the pain is often worst on the side you are lying on and eases when you roll off it.

Cause 2: The top leg pulling the pelvis out of line

The pain is sometimes coming from a twist, not the pressure. When you lie on your side with nothing between your knees, the top leg drops forward and down towards the mattress. That rotates the pelvis, stretches the muscles across the outside of the lower hip and pulls the lumbar spine into a slight twist. The hip you feel in the morning may be the one on top, not the one you were lying on, and the ache often comes with a stiff lower back. This is the same mechanism behind much of the lower back pain people get in bed.

Cause 3: The wrong mattress for a side sleeper

Side sleeping asks more of a mattress than any other position. Your hip and shoulder are the widest points, and the mattress needs to let them sink far enough that your spine stays straight, while holding your waist up. Too firm and the hip takes all the pressure (Cause 1). Too soft, or too old, and the hip sinks into a dip while the waist follows, so the spine sags in the middle. Either way, the joint spends the night under load it should not be carrying.

Cause 4: The joint or the tendons themselves

Sometimes the bed is only revealing a problem that was already there. Osteoarthritis of the hip tends to hurt in the groin or the front of the thigh and to stiffen after rest. Trochanteric bursitis or gluteal tendinopathy hurts on the outside of the hip, is tender to press and is often worse in women over forty. Lying on that side simply makes an irritated tissue impossible to ignore. Pain like this still responds to the position fixes below, but it usually needs some strengthening work too.

Is this your hip?

Hip pain when sleeping on your side: what to do about it

The fix follows the cause, so start with the changes that cost nothing and work down the list.

Step 1: Put a pillow between your knees

This is the single most effective change for Cause 2 and it helps with Cause 1 too. A pillow between the knees stops the top leg dropping forward, keeps the pelvis level and takes the twist out of the lower back. An ordinary bed pillow works to start with but tends to slide out or flatten by 3am. A shaped knee pillow stays put and holds the knees at hip width all night, which is what it needs to do. The DreamPad knee pillow is made for exactly this: a contoured memory foam wedge that sits between the knees and keeps the hips, pelvis and spine in a straight line while you sleep on your side. It will not fix an inflamed tendon or an arthritic joint on its own, but it removes the nightly strain that keeps them irritated. Our knee pillow buyer's guide explains what to look for in shape and firmness, and you will find it with our other posture aids in the sleep posture collection.

Step 2: Sleep on the other hip, and slightly back

If the pain is mainly Cause 1 or Cause 4, give the sore hip a break by sleeping on the other side for a couple of weeks. Rolling slightly back, so a pillow behind you takes some of the weight off the point of the hip, spreads the pressure over a larger area. If both hips hurt, try a short spell on your back with a pillow under the knees, which takes all the side pressure off. Our guide to the best sleeping position weighs up the options.

Step 3: Soften the contact point

For Cause 3 you may not need a new mattress straight away. A mattress topper of five to seven centimetres of memory foam or soft latex lets the hip sink in without the whole bed becoming soft, and it is a fraction of the price. If your mattress has a visible dip or is past its useful life, a topper will only mask it for so long - a medium-firm mattress suits most side sleepers best.

Step 4: Strengthen what supports the hip

Cause 4 responds to loading, not just rest. The muscles on the outside of the hip, particularly the gluteus medius, hold the pelvis steady and take strain off the tendons. Simple side-lying leg raises, clamshells and bridges done three or four times a week make a real difference over a month or two. If pressing on the outside of the hip is sharply painful, a physiotherapist can confirm whether it is a tendon problem and tailor the exercises.

Step 5: Manage the flare-ups

On a bad night, ten minutes with an ice pack wrapped in a tea towel on the outside of the hip before bed can calm an inflamed bursa. Avoid sitting cross-legged or with the legs crossed during the day, and avoid lying directly on the sore hip until it has settled. Over-the-counter anti-inflammatories help some people for short spells; ask a pharmacist if you take other medication.

"Side sleeping is bad for your hips, so I should sleep on my back" - is that true?

Partly. Side sleeping does put more pressure on the hip than lying on your back, and for someone with a badly inflamed bursa a spell on the back can be a genuine relief. But side sleeping is also the position most people find easiest to fall asleep in, it keeps the airway more open than lying flat, and it is the position doctors recommend in pregnancy and for people who snore. Most people who try to switch wholesale to back sleeping roll over within an hour anyway. The better answer for most is to make side sleeping work properly, with the knees supported and the hip allowed to sink, rather than to fight your own body all night.

When it's different for you

• If you are pregnant: hip and pelvic pain on your side is very common, especially in the third trimester, and side sleeping is still the advised position. A knee pillow plus a pillow under the bump helps most; we cover this in detail in our guide to sleep during pregnancy. Tell your midwife about pelvic girdle pain, which needs its own support.
• If you have a hip replacement: follow the sleeping advice from your surgeon, which often includes a pillow between the knees to stop the leg crossing the midline. Do not change position or use a wedge without checking it fits their instructions.
• If you have diagnosed osteoarthritis: the position changes above still help, but the bigger gains come from a strengthening programme. Ask your GP about a referral to physiotherapy or a supported exercise scheme.
• If the pain came on after a fall or is in a child or teenager: skip the self-help steps and see a doctor first.

When to see your GP

Frequently asked questions

Does a knee pillow really help hip pain at night?

For pain caused by the pelvis twisting, yes, and often quickly. A pillow between the knees keeps the top leg from dropping forward, holds the hips level and takes the strain off the muscles and tendons on the outside of the hip. The DreamPad knee pillow is shaped to stay in place all night, which a normal pillow rarely does. It will not cure arthritis or bursitis, but it removes a nightly aggravation.

Should I sleep on the painful hip or the other one?

Sleep on the other one while the sore hip settles, and roll slightly back onto a pillow so the bony point is not taking your full weight. If both hurt, a spell on your back with a pillow under the knees takes all the side pressure off. Once the pain has calmed, you can usually return to your preferred side with a knee pillow in place.

Is my mattress causing my hip pain?

Possibly, if it is very firm, very soft, or more than seven or eight years old. Side sleepers need a mattress that lets the hip and shoulder sink while supporting the waist. Try a memory foam or latex topper first; if you can see a dip or you sleep noticeably better in hotel beds, the mattress itself is probably due for replacement. Our ideal bedroom setup guide covers what to look for.

Why does my hip only hurt at night and not during the day?

Because during the day you move constantly and the hip is never under sustained pressure. At night you can lie on the same point for hours. Tendons and bursae that are mildly irritated cope fine with movement but not with being compressed without a break, so the ache builds through the night and eases once you get up and moving.

What is trochanteric bursitis and how do I know if I have it?

It is inflammation of the fluid-filled cushion over the bony point on the outside of the hip, now often called greater trochanteric pain syndrome because the tendons are usually involved too. The giveaways are pain on the outer hip that is tender to press, worse lying on that side, and worse after sitting or climbing stairs. It usually improves with a knee pillow, avoiding the sore side, and gluteal strengthening; a GP or physiotherapist can confirm it.

The bottom line

Start with a pillow between the knees, give the sore hip a break by sleeping on the other side with a pillow behind you, soften the contact point with a topper if the mattress is too firm, then build up the muscles that support the hip. Keep the flare-up measures for bad nights. In that order, most side sleepers get relief within a couple of weeks.

An achy hip after a night on a hard bed is nothing to worry about and is usually gone by the time the kettle has boiled. Pain that lasts weeks, sits in the groin, or wakes you when you are not even lying on it deserves a proper look from your GP rather than another pillow.

Try the DreamPad Knee Pillow - keeps your hips level and your spine straight, all night, without sliding out.

This article is general information, not medical advice. If your symptoms are persistent or severe, or you are unsure what is causing them, please speak to your GP. SleepyDeepy products are designed to support your sleep and are not a treatment for any medical condition.

Kinder nights, brighter mornings. SleepyDeepy.