Bursitis refers to the irritation or inflammation of the bursa, a sac with lubricating fluid which acts as a cushion between the bones and tendons, muscles and skin. The primary function of the bursa is to decrease the friction and rubbing between the bones and above mentioned body parts. Bursitis may set in due to age, sudden injury or repetitive usage of the joint over long period of time.

The high risk activities that may result in bursitis include carpentry, gardening, golf, pitching, scrubbing, and shoveling. Other possible causes include incorrect sitting posture and insufficient stretching before starting exercising. Certain conditions such as gout, psoriatic arthritis, rheumatoid arthritis and certain medications can increase the risk of catching bursitis. The body parts that are affected by this condition include elbow, shoulder, hip, knee and Achilles tendon.