Hip pain can make it hard to walk, go up and down stairs, squat, or sleep on the side that hurts. A clicking or snapping feeling or sound around your hip joint (snapping hip) may bother you or cause you to worry.
Hip problems may develop from overuse, bone changes with age, tumors, infection, changes in the blood supply, or a problem that was present from birth (congenital). Oddly enough, a person who has a hip problem often feels pain in the knee or thigh instead of the hip.
How Hip works
It is the largest ball-and-socket joint in the body. The thighbone (femur) fits tightly into a cup-shaped socket (acetabulum) in the pelvis. The hip joint is tighter and more stable than the shoulder joint but it does not move as freely. The hip joint is held together by muscles in the buttock, groin, and spine; tendons; ligaments; and a joint capsule. Several fluid-filled sacs (bursae) cushion and lubricate the hip joint and let the tendons and muscles glide and move smoothly. The largest nerve in the body (sciatic nerve) passes through the pelvis into the leg.
Causes of Hip Pain
While many causes of hip pain can arise from the joint itself, there are numerous structures surrounding the hip that can also be the source of pain.
Trauma is often the cause of hip pain, but any source of inflammation may cause pain in the hip area. Pain is one of the symptoms of inflammation, along with swelling, warmth, and redness; together these are signals and symptoms that a problem may exist.
Pain may arise from structures that are within the hip joint or from structures surrounding the hip.
The hip joint is a potential space, meaning that there is a minimal amount of fluid inside it to allow the femoral head to glide in the socket of the acetabulum. Any illness or injury that causes inflammation will cause this space to fill with fluid or blood, stretching the hip capsule lining and resulting in pain.
The femoral head and the acetabulum are lined with articular cartilage that allows the bones to move within the joint with less friction. Also, the socket area of the acetabulum is covered with tough cartilage called the labrum. Just like any other joint cartilage, these areas can wear away or tear and become the source of pain.
There are thick bands of tissue that surround the hip joint, forming a capsule. These help maintain the hip joint stability, especially with movement.