Bursitis

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Medical Author:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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Medical Editor:

Jerry R. Balentine, DO, FACEP

Jerry R. Balentine, DO, FACEP

Dr. Balentine received his undergraduate degree from McDaniel College in Westminster, Maryland. He attended medical school at the Philadelphia College of Osteopathic Medicine graduating in1983. He completed his internship at St. Joseph's Hospital in Philadelphia and his Emergency Medicine residency at Lincoln Medical and Mental Health Center in the Bronx, where he served as chief resident.

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• Bursitis Overview
• Bursitis Causes
• Bursitis Symptoms and Signs
• When to Seek Medical Care
• Bursitis Diagnosis
• Bursitis Treatment
• Self-Care at Home
• Medical Treatment
• Follow-up
• Bursitis Prevention
• Bursitis Prognosis
• Bursitis Pictures
• Synonyms and Keywords
• Authors and Editors
• Read more on Bursitis from Healthwise
• Viewer Comments: Bursitis - Describe Your Experience
• Viewer Comments: Bursitis Shoulder - Treatment

Bursitis Overview

A bursa is a fluid-filled sac that cushions an area of friction between tissues, such as tendon and bone. Bursae reduce friction between moving parts of the body, such as in the shoulder, elbow, hip, knee, and heel.

The number varies, but most people have about 160 bursae throughout the body. Bursae are lined with special cells, called synovial cells, which secrete a fluid rich in collagen and proteins. This synovial fluid acts as a lubricant when parts of the body move. Inflammation of a bursa is referred to as bursitis.

Bursitis Causes

The most common causes of bursitis are repetitive motions (for example, repeated throwing of a ball), trauma (extensive kneeling), infection, and preexisting rheumatoid conditions.

Trauma

Trauma causes inflammatory bursitis from repetitive injury or direct impact.

• Chronic bursitis: The most common cause of chronic bursitis is minor trauma that may occur to the shoulder (subdeltoid) bursa from repetitive motion, for example, throwing a baseball. Another example is prepatellar bursitis (in front of the knee) from prolonged or repetitive kneeling on a hard surface to scrub a floor or lay carpet.
• Acute bursitis: A direct blow (let's say you accidentally bang your knee into a table) can cause blood to leak into the bursa. This causes pain as well as swelling.

Infections

Bursae close to the surface of the skin are the most likely to get infected with bacteria, a condition that is called septic bursitis. The most common bacteria to cause septic bursitis are Staphylococcus aureus or Staphylococcus epidermis. People with diabetes, alcoholism, certain kidney conditions, those taking cortisone medications (steroid treatments), and those with wounds to the skin over a bursa are at higher risk for septic bursitis. About 85% of septic bursitis occurs in men.

Rheumatoid conditions

People with certain diseases such as gout and pseudogout can develop bursitis from crystal deposits. When these crystals form in a bursa, they cause inflammation leading to bursitis.