Lyme disease testing can be unreliable. You should be prepared to ask these five questions to your physician if your tests comes back negative.
For many illnesses, doctors rely on lab tests for diagnosis. Based on your symptoms, they have suspicion of what’s going on, and then run tests to confirm that suspicion. You may assume the same is true for Lyme disease. But because current Lyme disease tests only look for antibodies against the Lyme bacteria, not the bacteria itself, they are unreliable—so unreliable, in fact, that more than 50% of tests can be false negative.
What many people don’t realize is that Lyme disease is a clinical diagnosis. According to the CDC, a doctor should make a Lyme diagnosis based on your symptoms, medical history, tick exposure, and geographic area. Blood tests can help support that diagnosis, but they shouldn’t be used alone to determine if you do or don’t have Lyme. If your blood test comes back negative, that doesn’t necessarily mean you don’t have Lyme disease. If you suspect you may have Lyme and your test comes back negative, there are several questions you should ask your doctor:
Do my symptoms and history point to Lyme disease?
If you have an Erythema Migrans (EM) rash, often shaped like a bullseye, that is a definitive sign of Lyme disease. Other common symptoms of Lyme include fever, fatigue, aches, chills, and swollen lymph nodes. The more a Lyme infection progresses, the further it spreads; it can affect every organ and system of the body, causing a wide variety of symptoms. For this reason, your doctor should take into consideration your complete medical history, not just your current symptoms. They also should take into account whether you have had a known or suspected tick bite, and whether you live in or have traveled to an area where Lyme is endemic (remembering that Lyme is not just in New England!).
What test was run?
The CDC recommends a two-step testing process. The first test is called an ELISA. If that test comes back negative, the CDC doesn’t recommend doing the second test. However, because so many ELISA tests are falsely negative, this means many people who have Lyme don’t actually get the second, more specific test. If your test comes back negative, ask if only the ELISA test was run, or if the second test (Western, Blot, or another ELISA) was done. If only the first ELISA was done, ask if you can do the second test.
If the second test was a Western blot, how many bands were positive?
The Western blot test measures your immune system’s reactivity against a panel of proteins found on the Lyme bacteria, which show up as bands on your test results. According to the CDC, you need to have five positive bands in order for your test to be considered positive. A doctor may tell you your test is negative even if you have four positive bands, simply because it doesn’t meet the strict CDC criteria. However, if you have any positive bands, that means you have antibodies against Lyme disease, which means you could have it or could have been exposed to it at some point.
Which lab was used?
Some labs look for more specific bands than others. You can ask your doctor to send your blood work to one of these labs.
Could I have another tick-borne illness?
It is possible to be bitten by a tick and get an illness like babesiosis or anaplasmosis, but not get Lyme disease. Just because you don’t have Lyme disease, or don’t have a positive Lyme test, doesn’t mean you don’t have another tick-borne illness. Ask your doctor to consider the symptoms of other tick-borne illnesses when making a clinical diagnosis, and to test for them.
A good Lyme Literate Medical Doctor (LLMD) will consider all of these questions when making a clinical diagnosis. Click here to find one in your area.
Since Lyme disease is the great imitator and symptoms are similar to so many other illnesses, your doctor should consider every possibility when making a diagnosis. But Lyme should not be quickly ruled out based on a test. Don’t take “no” for an answer until you’ve explored all of these questions with an LLMD.
The above material is provided for information purposes only. The material (a) is not nor should be considered, or used as a substitute for, medical advice, diagnosis, or treatment, nor (b) does it necessarily represent endorsement by or an official position of Global Lyme Alliance, Inc. or any of its directors, officers, advisors or volunteers. Advice on the testing, treatment or care of an individual patient should be obtained through consultation with a physician who has examined that patient or is familiar with that patient’s medical history.