Chronic Lyme arthritis is a recurring form of joint inflammation caused by Lyme disease, a bacterial infection that is spread through tick bites. Symptoms of chronic Lyme arthritis include episodes of swelling, redness, and fluid buildup in one or more joints that last up to 6 months at a time.

When a person is not treated for Lyme disease, chronic Lyme arthritis can develop. Some experts believe chronic Lyme arthritis is caused by an exaggerated response of the body's immune system.

Chronic Lyme arthritis usually responds to antibiotic treatment. But joints that have been badly damaged by Lyme arthritis may take a long time to get better after the bacteria have been killed. Sometimes antibiotic treatment does not help the joints at all.