Hip pain when lying on your side at night — what causes it?

You settle into bed, roll onto your usual side, and there it is — a deep ache on the outer part of your hip that wakes you up or keeps you from dropping off. You flip to the other side, prop a pillow, shift around, and still can't get comfortable. If this sounds familiar, you are far from alone. Hip pain that shows up when you lie on your side is one of the most common hip complaints people bring to a clinician, and it has a handful of usual explanations.

This article walks through what tends to cause that night-time outer-hip pain, what usually helps, and which kind of professional to see. It is here to help you understand your options and ask better questions — not to diagnose you. Only a qualified clinician who can examine you in person can tell you what is actually going on with your hip.

Why lying on your side hurts

Here is the key idea that makes a lot of this make sense: when you lie on your side, your body weight presses the outer hip down into the mattress. On the bony bump you can feel there — the top of your thigh bone, called the greater trochanter — several tendons from your buttock muscles attach, with small fluid-filled cushions nearby. Lying on that side squeezes and compresses those tendons against the bone. If the tissue there is already irritated, that squeeze is exactly what sets off the ache [3]. It is why night pain, and pain when you lie on the sore side, is such a classic pattern.

That compression idea also explains why the pain can flare when you cross your legs or stand with your weight slumped onto one hip — both pull the thigh across your body and press on the same spot [3].

The common causes

A few things tend to be behind side-lying hip pain. A clinician sorts between them by examining you, but it helps to know the usual suspects.

Gluteal tendinopathy — often called "hip bursitis." This is the most common cause of pain on the outer side of the hip [1]. For years it was blamed on an inflamed bursa (the little cushion), which is where the "bursitis" label comes from. But when researchers looked closely with imaging, the main problem was usually the tendons of the buttock muscles being overloaded and irritated, not the bursa on its own [2]. That is why clinicians now often use the broader term greater trochanteric pain syndrome (GTPS). The distinction matters because it changes what tends to help — the focus shifts from calming inflammation to gradually rebuilding the tendons' ability to handle load. This kind of pain is most common in women in their 40s to 60s, though anyone can get it, and it often comes on gradually without a single injury [2]. Night pain from lying on the side is one of its hallmark features. We cover this in depth in our lateral hip pain and GTPS guide.

Hip osteoarthritis. Osteoarthritis is age-related change in the joint itself. It more typically causes pain in the groin or front of the hip, along with stiffness after resting and a gradual loss of movement, and it is a common cause of hip pain in older adults [1]. It can be part of the picture at night, and it sometimes sits alongside tendon pain rather than instead of it. Our hip osteoarthritis and exercise guide explains what the evidence shows.

Pain referred from your lower back. Not all "hip" pain comes from the hip. Problems in the lumbar spine can send pain into the buttock and outer hip area, and this referred pain can overlap with the pattern of tendon pain, which is one reason self-diagnosis is tricky [1]. A hands-on assessment is often what tells these apart.

Often more than one of these is going on at once, which is another reason a proper examination is worth it rather than guessing [1].

What tends to help

The good news is that the most common cause — gluteal tendinopathy / GTPS — usually responds to fairly simple, active care, and there are things you can try at home to take pressure off at night.

Ease the night-time compression. Because lying on the sore side squeezes the tendons, sleep position is a practical place to start. Patient information from the UK's NHS suggests trying to lie on your back with a pillow under your knees, or on your good side with a pillow between your legs so your top leg doesn't drop across your body and compress the hip [5]. Small changes like these are aimed at giving the irritated tissue a break overnight.

Adjust daytime habits. During the day, easing off the positions that compress the area — crossing your legs, "hanging" your weight onto one hip when you stand, and very low, soft chairs — is commonly encouraged [3][5]. Complete rest usually isn't the goal; the idea is to dial back what clearly flares it while staying active in ways the hip tolerates [5].

Build the tendons back up gradually. For tendon-related hip pain, graded strengthening of the buttock muscles is the best-supported approach — and it takes patience, because tendons adapt slowly [4][5].

On which professional to see: a physiotherapist (physical therapist) is a common first stop for this kind of pain. Physiotherapists are trained to examine the hip, help sort out whether the pain is coming from the tendons, the joint, or the back, and build a graded exercise and activity plan suited to you. In Canada you generally do not need a doctor's referral to see one privately, though some extended-health insurance plans ask for one before they reimburse — worth checking your plan.

What does the evidence say about that approach? For gluteal tendinopathy, one of the better trials — the LEAP trial, published in the BMJ in 2018 — compared education plus exercise against a corticosteroid (cortisone) injection and against a "wait and see" approach in 204 people. At 8 weeks, 77% of the education-plus-exercise group reported feeling much better, versus 58% for the injection and 29% for waiting; at one year, the exercise group was still ahead at 78%, compared with 57% and 52% [4]. In plain terms, an active education-and-exercise plan outperformed both a cortisone shot and simply waiting, and the advantage lasted [4]. For hip osteoarthritis, a Cochrane review of the trials found that exercise produces a real but modest improvement in pain and function — genuine help, though not a dramatic or guaranteed one [6]. Neither of these is a promise for your hip, but they point to why active, exercise-based care is usually the recommended starting place.

A realistic timeline

If your pain does turn out to be gluteal tendinopathy, it helps to know this is not usually a quick fix. NHS patient information notes it often takes on the order of 6 to 9 months, and sometimes longer, to settle with the right approach, with good weeks and setback weeks along the way [5]. That is normal and not a sign you are doing it wrong — consistency over months tends to matter more than any single exercise.

When to get medical care promptly

Most side-lying hip pain builds up gradually and is not an emergency. But some situations call for prompt medical attention rather than waiting it out. See a doctor or seek urgent care if you have:

• Hip pain that started after a fall, an accident, or a specific injury — this can mean a fracture, which is a particular concern in older adults [1].
• An inability to put weight on the leg or to walk on it [1].
• Fever, or a hip that is hot, red, and swollen — this can signal a joint infection that needs urgent assessment.
• Night pain that is severe, unrelenting, or steadily getting worse, or pain with unexplained weight loss or a history of cancer.
• Numbness, pins and needles, weakness, or the leg giving way.

If any of these apply to you, let a clinician guide you rather than relying on a general article like this one.

The bottom line

Hip pain when you lie on your side is most often caused by irritated gluteal tendons — the condition long called "hip bursitis" and now usually termed greater trochanteric pain syndrome — because lying on that side compresses the sore tissue. Hip osteoarthritis and pain referred from the lower back are other possibilities, and sometimes more than one is at play. Simple steps like changing your sleep position and easing compression can help at night, and active, exercise-based care guided by a physiotherapist is the best-supported path for the most common cause. What a general article can't do is examine your hip and confirm what's actually going on — so if the pain is disturbing your sleep, limiting you, or not settling, it is worth booking an assessment.

Ready to find someone? You can browse and compare physiotherapists near you in the Clinic Directory by location and focus area, and reach out directly to book an assessment.

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