Bursitis is inflammation of a bursa, one of the small fluid-filled sacs that cushion the spaces between your bones, tendons, and muscles near a joint. These sacs normally reduce friction and allow smooth, pain-free movement. When a bursa becomes irritated or inflamed, the result is localized pain, swelling, and stiffness that can make everyday activities surprisingly difficult.
What Bursae Do in Your Body
Your body contains over 150 bursae. Each one is a thin, lubricated sac positioned at points where tissues would otherwise grind against each other. They absorb the wear-and-tear of movement, especially around joints that bear weight or undergo repetitive motion. When they’re healthy, you never notice them. When one becomes inflamed, the joint it protects can feel stiff, achy, or sharp with certain movements.
Where Bursitis Happens Most
The four most common types are prepatellar (front of the kneecap), olecranon (tip of the elbow), trochanteric (outer hip), and retrocalcaneal (back of the heel near the Achilles tendon). Shoulder bursitis, specifically in the bursa beneath the top of the shoulder blade, is also extremely common. These locations share a pattern: they’re all spots where bone sits close to the skin surface or where tendons repeatedly slide over bone.
Knee bursitis often shows up in people who kneel frequently, like flooring installers or gardeners. Elbow bursitis is common in people who lean on hard surfaces for long periods. Hip bursitis tends to affect runners and people who sleep on one side. Shoulder bursitis frequently develops from overhead activities like painting, swimming, or reaching into high cabinets repeatedly.
What Causes It
The most common cause is prolonged pressure on the bursa, where it gets compressed between a hard surface and the bone underneath. Think of kneeling on a hard floor for an extended period. The second major cause is repetitive motion. Any activity that forces the same joint through the same movement pattern hundreds of times can irritate the bursa lining and trigger inflammation.
Direct trauma is the next most frequent trigger. A fall onto your knee or a blow to your elbow can inflame the bursa quickly. This type of traumatic bursitis also raises the risk of a more serious form called septic bursitis, where bacteria enter through a break in the skin and infect the bursa fluid.
Certain medical conditions also make bursitis more likely. Rheumatoid arthritis, osteoarthritis, gout, lupus, and scleroderma all create systemic inflammation that can spill over into the bursae. If you have one of these conditions and develop recurring bursitis, the underlying disease is often driving it.
What Bursitis Feels Like
The hallmark is a localized ache or tenderness right over the affected joint. The area may look visibly swollen, especially in superficial locations like the kneecap or elbow where the bursa sits just below the skin. The joint typically feels stiff and the pain worsens with movement or pressure. Lying on a hip with trochanteric bursitis at night, for example, can be intensely uncomfortable.
Bursitis pain is usually gradual when caused by repetitive stress. It starts as a mild soreness and builds over days or weeks. Traumatic bursitis tends to come on faster, within hours of an injury. If the area is red, warm to the touch, and you develop a fever, that pattern suggests a possible infection rather than simple inflammation.
Septic Bursitis: The Serious Version
Most bursitis is non-infectious. Your bursa is inflamed from mechanical irritation, not bacteria. But septic bursitis, where the bursa itself becomes infected, requires different and more urgent treatment. It most often happens when bacteria enter through a cut, scrape, or puncture wound near the joint.
The only reliable way to distinguish septic from non-septic bursitis is by analyzing fluid drawn from the bursa with a needle. In septic cases, the fluid contains a high concentration of white blood cells, predominantly the type that fights bacterial infections. A white blood cell count above 2,000 per cubic millimeter in the fluid is about 94% sensitive for detecting infection. Cultures of the fluid confirm which bacteria are responsible and guide treatment.
If you have bursitis with redness, warmth, fever, or rapidly worsening symptoms, the possibility of infection is something your doctor will want to rule out promptly.
How Bursitis Is Treated
Most non-septic bursitis responds well to conservative measures. The initial approach follows the familiar RICE framework: rest the affected joint, apply ice for 10 to 20 minutes at a time with a barrier between the ice and your skin, use gentle compression if the area is swollen, and elevate the joint above heart level when possible. Over-the-counter anti-inflammatory pain relievers help manage both pain and swelling.
The rest phase matters more than people expect. Continuing the activity that caused the inflammation almost guarantees the bursitis will persist or worsen. Even a few days of avoiding the triggering movement can make a noticeable difference.
When bursitis doesn’t improve with these basic steps, corticosteroid injections are a common next option. Delivered directly into or near the inflamed bursa, often guided by ultrasound for precision, these injections can provide significant and lasting relief. In one study of shoulder bursitis patients, average pain scores dropped from about 8 out of 10 before injection to 2.4 at six months, with minimal side effects.
Physical therapy plays a key role once the acute inflammation subsides. A therapist gradually reintroduces controlled stress to the joint, rebuilds strength in the surrounding muscles, and restores flexibility. This step is critical for preventing the bursitis from coming back.
When Surgery Becomes an Option
Surgery for bursitis is uncommon and reserved for cases that fail to respond to at least six months of conservative treatment, including physical therapy and injections. The procedure, called a bursectomy, removes the inflamed bursa entirely. It’s typically done arthroscopically through small incisions.
Outcomes are generally favorable. In studies of arthroscopic bursectomy, pain scores dropped by roughly half after surgery, and 65% of patients reported satisfaction levels of 80% or higher. About 10% needed a follow-up procedure. It’s a safe option when nothing else has worked, but it’s genuinely a last resort for most people.
Preventing Bursitis From Recurring
Because bursitis is driven by mechanical stress, prevention comes down to reducing the forces on vulnerable joints. If your bursitis is in your knees, use kneeling pads or cushioned knee braces during activities that put you on the ground. For elbow bursitis, avoid prolonged leaning on hard surfaces. For hip bursitis, a pillow between your knees while sleeping can reduce pressure on the outer hip.
Strengthening the muscles around the affected joint is one of the most effective long-term strategies. For shoulder bursitis, exercises that target the rotator cuff and shoulder blade muscles are particularly helpful. These include shoulder blade squeezes, wall push-ups, and resisted internal and external rotation exercises using a resistance band. The goal is to improve how the joint tracks during movement so the bursa isn’t repeatedly pinched or compressed.
Warming up before physical activity, varying repetitive tasks throughout the day, and gradually increasing intensity rather than jumping into new activities all reduce the mechanical irritation that triggers bursitis in the first place. For people with underlying inflammatory conditions like gout or rheumatoid arthritis, keeping the primary condition well managed is the single most important preventive step.