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

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 United States. 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, taking place in activities that increase tick exposure, and having a pet that may carry ticks home.

Not everyone infected with the bacteria gets ill. If a person does become ill, the first symptoms resemble the flu and include fever, headache, chills, muscle pain, and lethargy.

There may be a "bulls-eye" rash, a flat or slightly raised red spot at the site of the tick bite often with a clear area in the center. This lesion can be larger than 1 to 3 inches wide.

Stiff neck, joint inflammation, body-wide itching, unusual or strange behavior, and other symptoms may be seen in persons with later stages of the disease.

Note: Deer ticks can be so small that they are almost impossible to see. Therefore, many people with Lyme disease never even saw a tick. These people are more likely to develop symptoms because the tick remained on their body longer.

A blood test can be done to check for antibodies to the bacteria that causes Lyme disease. The most common one used is the ELISA for Lyme disease test. A western blot test is done to confirm ELISA results.

A physical exam may reveal signs of joint, heart, or brain problems in persons with advanced Lyme disease.