This is a swelling of a fluid-filled sac in the back of your elbow. This sac is called the “olecranon bursa.” You have similar sacs near other large joints throughout your body. They act as cushions between your bones and your soft tissues. Normally they have a small amount of fluid inside them. But sometimes they can swell. That is called “bursitis.”
Your olecranon bursa can swell if you injure your elbow by hitting it hard. It can swell if you put pressure on it, repeatedly, usually over months. That can happen if you have a job that requires you to crawl or to lean on your elbows a lot. The bursa can swell because of an infection in your elbow. And, swelling may be linked to conditions like arthritis or gout.
Symptoms may include swelling and pain. If you have an infected bursa, the skin of your elbow may feel red and warm. An infected bursa can cause serious illness.
Treatment depends on your needs. The swelling may go down if you cushion your elbow with a pad and avoid leaning on your elbow. Medications may help, too. Your doctor may remove fluid from the bursa with a needle. If those options aren’t helpful, or if you have an infected bursa, you may need surgery. Your healthcare provider can create a plan that’s right for you.