Definition of Lyme disease:

Lyme disease is an inflammatory disease spread through a tick bite.

This article offers a general overview on Lyme disease. For specific information see:

• Stage 1 Lyme disease
• Stage 2 Lyme disease
• Stage 3 Lyme disease

Causes, incidence, and risk factors:

Lyme disease is caused by the bacteria Borrelia burgdorferi (B. burgdorferi). Certain ticks carry the bacteria. The ticks pick up the bacteria when they bite mice or deer that are infected with Lyme disease. You can get the disease if you are bitten by an infected tick.

Lyme disease was first reported in the United States in the town of Old Lyme, Connecticut, in 1975. Cases have now been reported in most parts of the US. Most occur in the Northeast, upper Midwest, and along the Pacific coast. Lyme disease is usually seen during the late spring, summer, and early fall.

There are three stages of Lyme disease.

• Stage 1 is called primary Lyme disease.
• Stage 2 is called secondary Lyme disease.
• Stage 3 is called tertiary Lyme disease.

Risk factors for Lyme disease include walking in high grasses, doing activities that increase tick exposure, and having a pet that may carry ticks home.