What is bursitis?
Bursitis is the inflammation or irritation of the bursa. The bursa is a small sac filled with lubricating fluid, located between tissues such as bone, muscle, tendons, and skin. Bursae help to decrease friction, rubbing and irritation and help your joints move with ease. The more superficial bursae act as cushions between the skin and bone. There are more than 150 bursae in your body. Bursitis occurs when a bursa becomes inflamed or irritated; this results in pain and discomfort. The pain may be gradual (building up over time) or may be sudden and severe (especially if calcium deposits are present).
Where does bursitis occur?
Bursae are located throughout the body. However, certain joints are more subject to increased pressure and repetitive use, making bursitis more likely to develop in them. These joints include the shoulders, elbows, knees, and feet. Bursae near the hip joint, particularly those on the outer side of the hip, and those in the buttocks (subjected to pressure from sitting) are also prone to bursitis.
What causes bursitis?
Bursitis is most often caused by repetitive motions (i.e., overuse); or direct, minor impact on the area (such as from such activities as repeated bumping or prolonged pressure from kneeling). Less often, bursitis is caused from a sudden, more serious injury.
Other examples of the sources of bursitis include one or more of the following:
- Play or work activities that cause overuse or injury to the joint areas, for example:
- Sports (tennis, golf, throwing and pitching, etc.)
- Incorrect posture injury
- Stress on the soft tissues from an abnormal or poorly positioned joint or bone (such as leg length differences or arthritis in a joint)
- Other diseases or conditions (rheumatoid arthritis, gout, psoriasis, thyroid disease or an unusual drug reaction) and rarely, from infection
Many times, the cause of bursitis is unknown.