What is joint effusion?

Fluid is normally found in joints such as knees, hips, and elbows. When too much fluid builds up around a joint in your body, it's called joint effusion. When you have this problem, your joint may look swollen.

You might feel pain when you try to straighten a joint where you have fluid buildup. Your joint may be stiff or swollen.

Your doctor will do a physical exam. You may need an X-ray. You may need other imaging tests, like an ultrasound, MRI, or a CT scan. Your doctor may remove some fluid from your joint to learn more. This is called arthrocentesis. It's done by using a needle to drain fluid from your joint.

Home care can help you manage your symptoms. For example, rest the joint. Use a cold pack and prop up the joint when you sit or lie down. Ask your doctor if you can take an over-the-counter pain medicine, such as acetaminophen or naproxen.