A Lyme disease test checks your blood for antibodies to the Lyme disease bacteria. Lyme disease bacteria are spread by certain kinds of ticks.
Lyme disease can be hard to diagnose because its symptoms are similar to those of many other illnesses. If you and your doctor think you have Lyme disease, your doctor will ask about your medical history and do a physical exam. Antibody tests can sometimes be used to help identify Lyme disease. Other tests may be done in certain cases.
Antibody tests
Antibody tests are the most commonly used tests to help identify Lyme disease.
It may be several weeks after you were infected before antibodies can be found in a blood test. Once antibodies are in the blood, they usually stay in your system for many years, even after successful treatment of the disease. If you have antibodies to the Lyme disease bacteria, the test cannot tell if you were infected recently or sometime in the past.
There are two types of antibody tests to detect Lyme disease.
- Enzyme-linked immunosorbent assay (ELISA). This is a rapid test to identify Lyme disease antibodies.
- Western blot test. This test also identifies Lyme disease antibodies and can confirm the results of an ELISA test. It is most often done to detect a long-term (chronic) Lyme disease infection.
Your doctor will tell you which tests you need, depending on when you were bitten by a tick.
Other tests
Polymerase chain reaction (PCR) test. PCR testing can find the genetic material (DNA) of the Lyme disease bacteria. PCR testing may be used to identify a current (active) infection if you have symptoms of Lyme disease that have not gotten better with antibiotic treatment. The PCR test is a blood or urine test, but can also be done on fluid from the spine or from a joint.
Why It Is Done
A Lyme disease test is done to look for Lyme disease in people who have symptoms of Lyme disease. Symptoms may include:
- An expanding red rash with a pale center. This is sometimes called a "bull's-eye" rash.
- Extreme tiredness.
- Fever.
- Headache and stiff neck.
- Muscle and joint pain.
Symptoms of long-term (chronic) Lyme disease include joint pain, stiffness, and problems with the heart or nervous system.
Testing is most accurate when you have risk factors for Lyme disease or symptoms of the disease.
How To Prepare
In general, there's nothing you have to do before this test, unless your doctor tells you to.
How It Is Done
A health professional uses a needle to take a blood sample, usually from the arm.
How It Feels
When a blood sample is taken, you may feel nothing at all from the needle. Or you might feel a quick sting or pinch.
Risks
There is very little chance of having a problem from this test. When a blood sample is taken, a small bruise may form at the site.
Results
Test results are usually available in 1 to 2 weeks.
An antibody test checks to see if you've had an infection from a bacteria that causes Lyme disease.
- A normal (negative) test means that no Lyme disease antibodies are found. If the test is done in the first few weeks after an infection, there may not be enough antibodies in the blood yet. So if your doctor thinks you have Lyme disease, this test may be redone a few weeks later.
- An abnormal (positive) test means that Lyme disease antibodies are found. If antibodies are found, you may either have Lyme disease now or had the infection in the past. Once your blood tests positive for antibodies, it will likely continue to test positive for months to years, even when the bacteria are no longer present.
The polymerase chain reaction (PCR) test may be done to confirm a Lyme infection if you have a positive antibody test result.
- A negative PCR test means the test did not find Lyme disease bacteria DNA.
- A positive PCR test means the test found Lyme disease bacteria DNA.
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Current as of: September 30, 2025
