Radiology glossary

What does "bursitis" mean on your scan?

Part of: General orthopedic findings, explained

Full explainer: Bursitis — What It Means on Your Report

One of the body's small cushioning sacs is inflamed — a common cause of aching near joints. Bursae are thin, fluid-filled sacs that sit where tendons glide over bone, reducing friction — like tiny water balloons at high-friction spots. When irritated by overuse, prolonged pressure, or the same pinching that bothers nearby tendons, a bursa can become inflamed, swell with fluid, and hurt. The famous locations each have their flavor: the subacromial bursa above the rotator cuff (shoulder pain with overhead reaching), the trochanteric bursa at the outer hip (aching on the side of the hip, worse lying on it), the olecranon bursa at the elbow's tip (visible swelling after leaning), and the prepatellar bursa in front of the kneecap (housemaid's knee). Bursitis very often travels with tendinopathy, since the same mechanics irritate both. Most bursitis settles with rest from the aggravating activity and time; infected bursae — hot, red, with fever — are the exception that needs prompt care. The finding describes an irritated cushion, and context determines its importance.

What it means on Ultrasound

Ultrasound is excellent for bursitis: it shows the swollen, fluid-filled sac in real time, demonstrates whether it compresses with the probe (a useful sign), checks the adjacent tendon, and — a major advantage — guides a needle directly into the bursa for diagnostic or therapeutic injection. Quick, cheap, and radiation-free, it is the usual first test for a suspected inflamed bursa near the surface.

What radiologists look at next

For bursitis, the radiologist confirms the bursa's location — naming which one, since the body has dozens — measures its distension, and assesses its walls and contents: simple fluid versus thickened walls or debris that suggests chronicity or infection. They examine the structures the bursa serves: the adjacent tendon for tendinopathy, nearby bone for spurs that might be the irritant. Signs suggesting infection — marked wall thickening, surrounding edema, clinical correlation with redness and fever — are flagged explicitly, since septic bursitis changes management urgently.

Where it commonly shows up

• shoulder
• outer hip
• elbow
• kneecap
• subacromial bursa

Questions to ask your doctor

• Which bursa is inflamed?
• What is irritating it — overuse, pressure, or a nearby tendon problem?
• Is there any sign of infection?
• What should I avoid while it settles?
• How long does it usually take to resolve?

Common questions

What does bursitis feel like?

Typically a localized ache or tenderness over the bursa's spot, worse with pressure or the movement the bursa cushions — lying on an inflamed hip bursa, reaching overhead with shoulder bursitis, kneeling with kneecap bursitis. Swelling may be visible at superficial sites like the elbow. Your doctor confirms the pattern fits the bursa shown on imaging.

How is bursitis treated?

Most cases settle with rest from the aggravating activity, avoiding direct pressure, and time — the irritated cushion calms down once the irritation stops. Persistent cases sometimes receive a guided injection. Infected bursitis, marked by redness, warmth, and fever, needs prompt medical treatment. Your doctor will advise based on the cause and severity.

Will it come back?

It can, if the irritant returns — the same overhead workload, the same side-sleeping habit, the same pressure. Addressing the mechanics (posture, technique, padding, load) is what prevents recurrence. Think of the first episode as information about what the bursa cannot tolerate; your doctor or therapist can help redesign the habit.

Related conditions

• Tendinopathy — What It Means on Your Report
• Joint Effusion — What It Means on Your Report
• Rotator Cuff Tendinopathy — What It Means on Your Report