Side sleeping is the most popular position in the country, and with hip or knee arthritis it is also the most complicated. Lie on the arthritic hip and it carries your weight all night; lie on the good side and the top leg drags the pelvis into rotation, straining the hip and knee from a different angle. The fix is a combination: the right surface, the right side, and a pillow in the right place. Here is how it fits together.
The surface: give at the hip, support at the waist
A side sleeper's hip is a pressure point by design, and an arthritic one doubly so. The mattress needs comfort layers deep enough for the hip to settle in and spread its load, on a surface that is too firm, the joint carries concentrated pressure and wakes you, while beneath, a pocket spring core must hold the pelvis level so the spine stays straight. Too soft fails in the opposite direction: the hips, the heaviest part of most bodies, sink through and the night is spent in a gentle sideways sag that hips and knees pay for by morning. Medium-firm with genuine surface cushioning is the reliable middle, and it is exactly the construction a good hybrid delivers.
“A pillow between the knees is the cheapest piece of arthritis equipment there is, and one of the most effective.”
The set-up: side, knees and pillow placement
Sleep on the unaffected side where you have one, taking the painful joint out of the loading position entirely. Then put a pillow between the knees: it stops the top leg dropping across the body, which keeps the pelvis stacked rather than rotated and takes twisting strain off both hips and the knees between them. For knee arthritis specifically, the pillow also stops bone-on-bone contact between the knees themselves, a small misery every side sleeper with knee pain recognises. Keep the knees gently bent rather than curled tight, tight flexion held for hours stiffens an arthritic knee, and if you end up on your back, a slim pillow under the knees relaxes the hips there too.
What we recommend
UK adults say pain interrupts their sleep and wakes them during the night.
Explore the UK Sleep StatisticsFrequently asked questions
Which side should I sleep on with hip arthritis?
The unaffected side, with a pillow between the knees to stop the pelvis rotating. If both hips are involved, or side sleeping stays painful whichever way you face, back sleeping on a supportive surface with a slim pillow under the knees is the position worth training yourself into.
Does a pillow between the knees really make a difference?
Yes, and it is probably the cheapest intervention on this page. It keeps the hips stacked instead of rotated, takes twisting strain off hip and knee, and stops the knees pressing on each other. An ordinary pillow works; a firmer one holds position better through the night.
My hip only hurts in bed, not during the day. Why?
Lying on your side loads the hip differently from standing, concentrated sideways pressure through the joint and the soft tissue over it, held for hours. It is a common pattern with hip arthritis and with trochanteric bursitis, which often accompanies it. If night hip pain persists despite a better surface and set-up, it is worth a GP or physiotherapist review to pin down which it is.
Related reading
This guide is part of our Sleep Health Hub. For the complete picture, read our full arthritis sleep guide, or the shoulder pain guide if the trouble sits higher up.
