Borrelia Antibody (Blood)
Does this test have other names?
Borrelia burgdorferi antibodies test, IgM/IgG test, Lyme disease test
What is this test?
This test measures the level of Borrelia antibodies in your blood. Borrelia burgdorferi
bacteria cause Lyme disease.
The bacteria are spread to humans through the bite of an infected tick.
Lyme disease is the most common tick-borne illness in the U.S. If not treated, Lyme
disease can cause an infection of the tissues covering the brain and spinal cord (meningitis).
It can also cause:
Liver and heart problems
Inability to control facial muscles (facial palsy)
Problems that may show up months or years later, such as ongoing pain and tiredness,
arthritis, and problems with memory and concentration
The CDC advises a 2-step evaluation of your blood test. First, your blood sample is
tested through a process called enzyme immunoassay (EIA) or indirect immunofluorescence
assay (IFA). If this is positive for Borrelia antibodies, the sample is put through
an immunoblot test. This is also known as a Western blot test. This test measures
immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies in your blood.
You will likely receive a diagnosis for Lyme disease if both the EIA/IFA and the Western
blot test are positive. But in some cases, you may also have other tests, such on
your cerebrospinal fluid (CSF).
Why do I need this test?
You may need this test if your healthcare provider thinks that you have Lyme disease
based on recent travel, physical exam, and symptoms. Symptoms include a red bump that
looks like a spider bite that spreads into a red rash in a classic bull's-eye pattern.
You may also have:
Swollen lymph nodes
Muscle and joint aches
What other tests might I have along with this test?
You may also have a test to look for Borrelia antibodies in your cerebrospinal fluid
(CSF) if you have signs that your central nervous system has been affected. This may
also be done if the blood test results aren't clear. CSF is the liquid that surrounds
the brain and spinal cord.
What do my test results mean?
Test results may vary depending on your age, gender, health history, the method used
for the test, and other things. Your test results may not mean you have a problem.
Ask your healthcare provider what your test results mean for you.
A negative result means that no antibodies were found. But Lyme disease is hard to
diagnose. This is partly because the antibodies may not show up in your blood for
several weeks. If your results are negative shortly after you've been infected, the
result could be a false-negative.
A positive result means that Borrelia antibodies were found and that you may have
Lyme disease. False-positive results sometimes do occur. This means the test could
say you have the infection when you don't.
False-positive results can also happen if you have the autoimmune disease lupus, HIV,
or syphilis. They can also happen if you have Helicobacter pylori bacteria or the
How is this test done?
The test is done with a blood sample. A needle is used to draw blood from a vein in
your arm or hand.
Does this test pose any risks?
Having a blood test with a needle carries some risks. These include bleeding, infection,
bruising, and feeling lightheaded. When the needle pricks your arm or hand, you may
feel a slight sting or pain. Afterward, the site may be sore.
What might affect my test results?
The Lyme disease vaccine might affect your test results. If you are tested too soon
after having been infected, you may get a false-negative result. If you have been
treated with antibiotics, your results may be affected.
How do I get ready for this test?
You don't need to prepare for this test. But be sure your healthcare provider knows
about all medicines, herbs, vitamins, and supplements you are taking. This includes
medicines that don't need a prescription and any illegal drugs you may use.