Olecranon bursitis is swelling of the small, fluid-filled sac that sits right over the bony point of your elbow. When this sac, called the olecranon bursa, becomes irritated or infected, it fills with extra fluid and produces a noticeable, squishy lump at the back of the elbow. It’s one of the most common types of bursitis and can range from a painless nuisance to a serious infection requiring prompt treatment.
What the Olecranon Bursa Does
Your elbow has a sharp bony tip called the olecranon, which is the part you lean on when you rest your arm on a table. The bursa is a thin, slippery sac that covers this bone, acting as a cushion between the bone and the overlying skin. It reduces friction so the skin can glide smoothly over the bone every time you bend and straighten your arm. Normally, the bursa contains only a tiny amount of fluid and you can’t feel it at all.
Common Causes
The most frequent trigger is repeated pressure on the elbow. Leaning on a hard desk for hours, crawling on your elbows, or resting your arm on a car door window can all irritate the bursa over time. This is why olecranon bursitis has earned nicknames like “student’s elbow” and “plumber’s elbow.” Occupations that put people on their elbows regularly, such as roofers, HVAC technicians, and plumbers, carry a higher risk.
A single direct blow to the elbow, like falling onto a hard surface or getting hit during a sport, can also set off sudden inflammation. In some cases, a cut or scrape over the elbow allows bacteria to enter the bursa, leading to an infected (septic) form of the condition. Systemic conditions play a role too. Gout is a well-known contributor because urate crystals tend to deposit in superficial structures that sit at lower body temperatures, and the olecranon bursa is a prime target. Rheumatoid arthritis and a crystal condition called calcium pyrophosphate deposition disease can also trigger bursitis at the elbow.
Septic vs. Aseptic Bursitis
Not all cases involve infection, and the distinction matters because treatment is very different. Aseptic bursitis, the non-infected kind, usually develops from repetitive pressure or an underlying inflammatory condition. It often presents as painless or only mildly uncomfortable swelling that feels soft and movable. You might notice it one day and realize it doesn’t really hurt unless you bump it.
Septic bursitis, on the other hand, involves a bacterial infection inside the bursa. The signs are more dramatic: about 88% of septic cases involve significant tenderness, 83% show skin redness or surrounding cellulitis, and 84% feel noticeably warm to the touch. Fever occurs in roughly 38% of infected cases. If you see redness spreading around the elbow, feel heat radiating from the swelling, or develop a fever alongside the lump, that pattern points toward infection rather than simple irritation.
What It Looks and Feels Like
The hallmark sign is a visible, egg-shaped swelling over the back of the elbow. The lump is typically soft and fluctuant, meaning it moves and compresses slightly when you press on it. In chronic or non-infected cases, you may have full range of motion and barely notice it unless you look at your elbow or lean on something hard.
When inflammation is more active, the area can be tender, warm, and red. The overlying skin sometimes shows signs of an old scrape, puncture, or callus from repeated pressure. Most people can still bend and straighten the arm normally, though significant pain or a large amount of swelling can start to limit motion. If the bursa is infected, even light contact with the elbow can be quite painful.
How It’s Diagnosed
A physical exam is usually enough to identify olecranon bursitis. The soft, localized swelling over the tip of the elbow is distinctive. When there’s concern about infection, a needle aspiration of the bursa fluid can confirm or rule out a bacterial cause. The fluid is sent for a cell count and a Gram stain. A white blood cell count above 2,000 per cubic millimeter in the fluid is about 94% sensitive and 79% specific for septic bursitis, though counts can climb much higher, averaging around 63,000 in confirmed infections. Even if the Gram stain comes back negative, a very high white cell count combined with clinical signs of infection is still treated as septic.
Complications from the aspiration itself are uncommon. The most notable risk is introducing bacteria into a previously sterile bursa, which is why the procedure is done with careful sterile technique and typically reserved for cases where infection needs to be confirmed.
Treatment for Non-Infected Cases
Most aseptic olecranon bursitis improves with straightforward measures. The first step is eliminating whatever caused the irritation. If leaning on your elbow triggered it, stop doing that. Applying ice to the area for 15 to 20 minutes several times a day helps reduce swelling, and over-the-counter anti-inflammatory medications like ibuprofen can ease both pain and inflammation.
A compression sleeve or elbow wrap can help push fluid out of the bursa and prevent it from refilling. Some people find it helpful to wear an elbow pad during the day, especially if their work requires arm contact with hard surfaces. In many cases, the swelling gradually resolves over a few weeks with these measures alone. If the bursa stays swollen, a healthcare provider may drain it with a needle and sometimes follow with a compression bandage to discourage reaccumulation.
When Infection Is Involved
Septic bursitis requires antibiotics. Fluid is typically aspirated both to identify the bacteria responsible and to relieve pressure. Mild cases can often be managed with oral antibiotics and close follow-up, while more severe infections with surrounding cellulitis or systemic symptoms may need stronger treatment. The key is catching it early: infected bursitis that goes untreated can spread to surrounding tissue or even into the bloodstream.
Surgery for Persistent Cases
When bursitis keeps coming back despite repeated aspirations, antibiotics, compression, and anti-inflammatory treatment, surgical removal of the bursa (bursectomy) becomes an option. This can be done through a traditional open incision or with an endoscopic technique using a small camera and instruments. Endoscopic bursectomy is generally preferred for straightforward recurrent cases because it involves smaller incisions and a faster recovery.
Open bursectomy is the better choice when the bursa is massively enlarged or packed with gout deposits (tophi), since the endoscopic approach has a higher risk of bursa rupture and recurrence if all the crystal deposits aren’t fully removed. After either type of surgery, it typically takes about 6 weeks for swelling to fully subside and for a return to normal activities.
Preventing Recurrence
If you’ve had olecranon bursitis once, you’re at risk for it returning unless you change the habits that triggered it. Wearing elbow pads during sports or physical work provides a direct cushion over the vulnerable area. A supportive elbow sleeve offers lighter protection for everyday activities. At a desk, avoid resting your bare elbow on hard surfaces for extended periods. A simple folded towel or gel pad under your arm can make a meaningful difference.
For people in high-risk trades, taking regular breaks from elbow-heavy positions and icing the elbow after a long day of work can reduce cumulative irritation before it becomes a full flare. If gout or another inflammatory condition is the underlying cause, keeping that condition well managed is the most effective way to prevent the bursa from filling up again.