Diagnosis and Testing

Lyme disease is diagnosed based on:

• Signs and symptoms
• A history of possible exposure to infected blacklegged ticks

Laboratory blood tests are helpful if used correctly and performed with validated methods. Laboratory tests are not recommended for patients who do not have symptoms typical of Lyme disease. Just as it is important to correctly diagnose Lyme disease when a patient has it, it is important to avoid misdiagnosis and treatment of Lyme disease when the true cause of the illness is something else.