If you suffer from hip pain, some doctors recommend placing a pillow between your knees while sleeping on your side at night in order to align your spine and hips. Doing so may help ease your symptoms and result in a better night's sleep. That's why the best pillows for hip pain are firm, thick, and able to support your legs.
Although any type of pillow that keeps your pelvis in a neutral position will work, a contoured pillow is ideal since it is more likely to stay in place between your legs and not move around while you sleep.
According to Dr. Wu, "as an individual and healthcare provider who has hip pain herself, typically any pillow that can support the weight of your leg and keep it level with the height of your hip when you are lying on your side will help. If you are taller, a longer pillow will be necessary as the pillow needs to support the thigh bone down to the ankle to keep the leg in alignment. If you are using the pillow in between your knees, then a contoured pillow that cradles both legs is more helpful, as a fluffy pillow can actually set your hips too far apart."