What causes hip, knee, and shoulder pain?

The most common cause of joint pain is arthritis and the most common form of arthritis is osteoarthritis. Knee pain caused by arthritis may come on gradually and get worse with activity. It is often accompanied by swelling. You may have stiffness after waking in the morning or after sitting for long periods of time. Another cause of knee pain is inflammation of the bursa, or bursitis. Bursae are jelly-like sacs in the joint area that usually contain a small amount of fluid. They act as cushions between bones and the overlying soft tissues, helping to reduce friction between the gliding muscles and the bone.

Bursitis can also be a cause of pain in the shoulder and hip areas.

Your trunk area includes the hips and pelvis; together they form the "pelvic girdle." The outer bony point of the hip is called the greater trochanter. It is an attachment point for muscles that move the hip joint. The trochanter has a large bursa overlying it that occasionally becomes irritated, resulting in hip bursitis (trochanteric bursitis). Pain in the joint of the hip is a common repercussion of arthritis and usually presents as pain located in the groin and front of the thigh.

Similar to hip pain, shoulder pain may also be present directly at the joints. Osteoarthritis is a frequent cause of shoulder joint pain. Other areas of the shoulder such as the bursa, rotator cuff or tendons can be additional sources of pain.