A bursa is a small fluid-filled sac that lets tendon glide smoothly over bone. There is one over the bony point at the side of your hip, and when the tendons running across it are too tight, it gets compressed and irritated.
The name is slightly misleading — the bursa is often not the main problem. More often it is the gluteal tendons themselves, which is why the condition is increasingly called greater trochanteric pain syndrome.
What usually causes it
- Weak glutes, letting the pelvis drop with every step so the tendons are repeatedly compressed against the bone.
- A tight IT band pressing down over the area.
- Sleeping on that side on a firm mattress, which compresses it for hours.
- A sudden increase in walking or running, especially on cambered roads.
What treatment involves
Releasing the tension in the IT band and the muscles around the outside of the hip that are compressing the area, and settling the referred pain from trigger points in the glutes.
Then strengthening the glutes, which is what stops it recurring — this is a tendon-under-compression problem, and the fix is to control the pelvis better.
One practical thing that helps immediately: sleep with a pillow between your knees. It stops the top leg dropping across and compressing the sore side all night.