Lyme Disease Tests
Reviewed
Lyme disease tests detect antibodies your immune system makes against the bacteria that cause Lyme disease. They are used to help diagnose infection after a tick bite, especially if you have symptoms. Tests are done on blood or, if nervous system involvement is suspected, on cerebrospinal fluid. Results are interpreted together with your symptoms and exposure history.
Preparation and collection
No special preparation for a blood test. For a lumbar puncture, you may be asked to empty your bladder and bowels beforehand.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- Test results alone cannot diagnose Lyme disease; your healthcare provider must consider your medical history, exposure, symptoms, and possibly other tests.
- Blood tests may be negative early in infection (false negative) because it takes weeks for antibodies to appear.
- Positive blood tests may be false positive (e.g., from other bacterial infections or autoimmune diseases) or from a past resolved infection.
- CSF test negative does not rule out nervous system involvement; more tests may be needed.
What to do next
Your healthcare provider will interpret your test results along with your symptoms, exposure history, and physical exam. If Lyme disease is likely, you will be prescribed antibiotics.