Bursitis

What a bursa does

The body has about 150 bursae. They are thin, slippery sacs containing a small amount of fluid that reduce friction between moving structures. Some lie just under the skin, such as over the elbow tip and kneecap. Others lie deep, beneath tendons, such as in the shoulder and hip.

When a bursa is irritated by repeated friction, pressure or injury, its lining thickens and makes extra fluid. This causes pain and swelling.

Common types of bursitis

Many cases of "trochanteric bursitis" are now recognized as tendinopathy of the hip abductor tendons, collectively called greater trochanteric pain syndrome. Treatment is similar.

Causes and risk factors

• repetitive movements: throwing, lifting overhead, running
• prolonged pressure: kneeling, leaning on elbows, sitting on hard surfaces
• direct blows or falls
• inflammatory arthritis: rheumatoid arthritis, gout and pseudogout
• infection, especially in bursae just under the skin
• diabetes, obesity and age over 40
• poor posture, leg length differences and weak muscles around the joint

Symptoms

• aching or burning pain near a joint
• tenderness when pressing over the bursa
• swelling, sometimes a soft fluid-filled lump
• pain worse with movement or pressure, such as lying on the side
• stiffness

Septic (infected) bursitis

Most often affects the elbow or knee bursae, after a cut, scrape or insect bite lets bacteria in, usually staph. Signs:

• redness and warmth spreading over the swelling
• marked tenderness
• fever and feeling unwell
• sometimes pus draining

It needs prompt medical assessment, aspiration of fluid, and antibiotics.

Diagnosis

A doctor will usually diagnose bursitis from the history and examination, pressing over the bursa and testing joint movement. Tests may include:

• aspiration: drawing fluid from a swollen bursa with a needle, to test for infection, crystals (gout) or blood
• ultrasound: shows fluid in the bursa and checks nearby tendons
• X-ray: for bone spurs, calcium deposits or arthritis
• MRI: for deep bursitis or when the diagnosis is unclear
• blood tests: for infection, gout or rheumatoid arthritis

Treatment

Home care

• Rest the area and avoid the activity that triggers pain
• Ice wrapped in a cloth for 15 to 20 minutes several times a day in the first days
• Padding: knee pads for kneeling, elbow pads, cushions for sitting
• NSAIDs such as ibuprofen or naproxen, following the label dose, to reduce pain and inflammation. Avoid them if you have kidney disease, stomach ulcers or heart failure
• Gentle movement to avoid stiffness, especially in the shoulder

Medical treatment

• Physical therapy: stretching and strengthening, particularly the hip abductors and rotator cuff
• Corticosteroid injection into or near the bursa, which often relieves pain quickly. Not used in suspected infection, and usually limited in number
• Aspiration of large, uncomfortable fluid collections
• Antibiotics for septic bursitis, oral for mild cases and IV for severe cases, with repeated drainage if needed
• Surgery: rarely needed. Removal of a chronically inflamed or repeatedly infected bursa (bursectomy)

Prevention

• use pads when kneeling or leaning
• take breaks during repetitive tasks
• warm up before exercise and build activity gradually
• strengthen muscles around the hips and shoulders
• maintain a healthy weight
• clean and cover cuts over the elbow and knee

Outlook

Most bursitis settles within a few weeks with rest and treatment, though deep bursitis in the hip or shoulder can take several months. It may recur if the triggering activity continues. Septic bursitis generally resolves fully with antibiotics and drainage.

Frequently asked questions

What causes bursitis?

Bursitis is usually caused by repetitive movement or prolonged pressure on a joint area, such as kneeling, leaning on elbows or overhead work. Injury, gout, rheumatoid arthritis and infection are other causes.

How long does bursitis last?

Most cases improve within 2 to 6 weeks with rest, ice and anti-inflammatories. Hip and shoulder bursitis can last several months. Bursitis can come back if the activity that caused it continues.

How do I know if bursitis is infected?

Infected bursitis is usually red, hot, very tender and swollen, sometimes with fever or a nearby skin break. It most often affects the elbow or knee. See a doctor promptly, as fluid may need to be drained and tested and antibiotics started.

What is the best treatment for bursitis?

Resting from the triggering activity, ice, padding and NSAIDs help most cases. Physical therapy addresses muscle weakness and posture. A steroid injection can relieve persistent pain. Infected bursitis needs antibiotics.

Is bursitis the same as arthritis?

No. Arthritis is inflammation inside a joint. Bursitis is inflammation of a cushioning sac outside the joint. Bursitis pain is usually more localized and tender to the touch, while arthritis affects joint movement more broadly.