An illness caused by borrelia bacteria that usually is spread through the bite of an infected tick.

Lyme disease is caused when a tick infected with borrelia bacteria feeds on a person and spreads the bacteria into the person's bloodstream. The risk of Lyme disease rises when visiting places where infected ticks might live. These include grassy, brushy or wooded areas.

Lyme disease symptoms vary. Early on, a circle-shaped rash is common, as is joint stiffness, muscle aches and pains and swollen lymph nodes. Later symptoms can include other rashes, neck pain and stiffness, muscle weakness in the face, and arthritis in large joints.

The treatment for Lyme disease is antibiotic medicine to clear up the infection. The medicine is taken by mouth or given through a vein. Recovery tends to better when treatment is started early.