What is Lyme Disease?
Lyme disease (Lyme borreliosis) is a bacterial infection spread by ticks. In various parts of the United States, different kinds of ticks carry the bacteria that can cause Lyme disease. Deer ticks spread Lyme disease in the northeastern and upper Midwestern United States. Western black-legged ticks spread the disease on the Pacific coast (mostly Northern California and Oregon). The ticks that spread Lyme disease are very small (about the size of a poppy seed or sesame seed), and their bite is usually painless.
Lyme disease develops in three stages. If a person is bitten by a tick carrying Lyme disease bacteria, a rash often (but not always) develops at the site of the tick bite within 1 to 31 days. The rash (which may look like a bull's-eye) slowly expands and may become very large. Flu-like symptoms may also occur.
This early stage of the disease is called Early Localized Lyme disease. If Lyme disease is not detected and treated properly during the early localized stage, the infection may progress to the second or third stages of Lyme disease that may involve the skin, joints, nervous system, and heart.
The second stage of Lyme disease, called Early Disseminated Lyme disease, may develop several weeks or months after a person becomes infected. It can cause problems with the skin, joints and some early nervous system complications.
The last stage of the disease, called Late Persistent Lyme disease, is often the most serious and may develop weeks, months, or, even years after the initial infection. It can cause joint and heart problems and/or late nervous system complications.