Bursitis
Whether you're at work or at play, if you overuse or repetitively stress your body's joints, you may eventually develop a painful inflammation called bursitis.

You have more than 150 bursae in your body. These small, fluid-filled sacs lubricate and cushion pressure points between your bones and the tendons and muscles near your joints. They help your joints move with ease. Bursitis occurs when a bursa becomes inflamed. When inflammation occurs, movement or pressure is painful.

Bursitis often affects the joints in your shoulders, elbows or hips. But you can have bursitis by your knee, heel and the base of your big toe. Bursitis pain usually goes away within a few weeks or so with proper treatment, but recurrent flare-ups of bursitis are common.

Symptoms
If you have bursitis, you may notice:

• A dull ache or stiffness in the area around your elbow, hip, knee, shoulder, big toe or other joints
• A worsening of pain with movement or pressure
• An area that feels swollen or warm to the touch
• Occasional skin redness in the area of the inflamed bursa

Bursitis of the hip doesn't cause any visible swelling or skin redness because the bursae are located beneath some of your body's bulkiest muscles. In this type of bursitis, pain is primarily over the greater trochanter, a portion of your thighbone (femur) that juts out just below where the bone joins the hip.

Causes
Common causes of bursitis are overuse, stress and direct trauma to a joint, such as with repeated bumping or prolonged pressure from kneeling. Bursitis may result from an infection, arthritis or gout. Many times, the cause is unknown.

Bursitis in certain locations of your body is caused by repetitive motion related to certain activities:

• Shoulder - Bursitis of the shoulder often results from injury to the rotator cuff, the muscles and tendons that connect your upper arm bone to your shoulder blade. Causes of the injury may include falling, lifting and repetitive overhead arm activities. Sometimes it's hard to distinguish between the pain caused by bursitis and that caused by a rotator cuff injury.
• Elbow - This type of bursitis is associated with actions requiring you to repeatedly bend and extend your elbow. You may get such an inflammation by pushing a vacuum cleaner back and forth. Throwing a baseball and swinging a tennis racket or a golf club are other examples of repeated physical activities that may lead to bursitis or tendinitis of the elbow or shoulder. Simple repeated leaning on your elbows could lead to bursitis over the tip of your elbow.
• Buttocks - This type of bursitis describes an inflamed bursa over the bone in your buttocks. It may result from sitting on a hard surface for long periods, such as on a bike.
• Hip - Bursitis of the hip is frequently associated with arthritis or a hip injury. The pressure from standing or sitting for a prolonged time may lead to bursitis of the hip.
• Knee - In this form of bursitis, a soft, egg-shaped bump occurs on the front of your knee, the result of repetitive kneeling while installing tiles, scrubbing a floor, gardening or doing other activities that place pressure on your knees. A sharp blow to the knee can cause inflammation of the bursae around the kneecap. People with arthritis who are overweight often develop bursitis of the knee.
• Ankle - Inflammation of the bursa in the ankle commonly occurs as a result of improper footwear or prolonged walking or in sports, such as ice-skating.

You may not be able to pinpoint a specific incident or activity that led to your bursitis. In some cases, the inflammation may stem from a staphylococcal infection.

Risk factors
If you work in a profession or have a hobby that requires repetitive motion, you're at an increased risk of developing bursitis. The occurrence of bursitis becomes more common in middle age. In addition, certain diseases and conditions increase your risk of developing bursitis, such as:

• Arthritis
• Gout
• Staphylococcal infection