Leukemias are cancers that involve certain cells of the body’s blood, bone marrow, or immune system. Lyme disease is a bacterial infection that people can catch from tick bites. Although these conditions are very different, certain connections may exist between them.

As a 2021 reviewTrusted Source explains, leukemias are cancers that develop from certain cells called leukocytes. When someone has leukemia, some of their leukocytes grow and divide in an uncontrolled fashion. Doctors can classify such cancers according to whether they affect myeloid or lymphoid cells. These cells are kinds of leukocytes.

As the review notes, there are many possible genetic and environmental causes of leukemia.

Lyme disease is the resultTrusted Source of Borrelia burgdorferi bacteria. These bacteria can make their way into a person’s body via tick bites. Ticks are small arachnids that feed on blood, and that can carry B. burgdorferi bacteria.

This article will look into the possibility that Lyme disease is a risk factor of leukemia. It will also look into what it is like to have both conditions at the same time, and at whether Lyme disease could mask or be mistaken for leukemia.  (See link for article)



  • some evidence showsTrusted Source that Lyme disease may increase a person’s risk for another type of blood cancer called lymphoma. This may be because of the inflammation that Lyme disease causes in the body.
  • evidenceTrusted Source that Lyme disease is a risk factor of lymphomas. But this risk is small, and the link is not clear.
  • American Cancer Society (ACS)Trusted Source notes that some people with a B. burgdorferi infection, which causes Lyme disease, developed skin lymphomas in Europe. But the ACS emphasizes that most individuals with Lyme disease will not develop skin lymphomas.
  • ScientistsTrusted Source believe that bacterial infections such as Lyme disease could increase a person’s cancer risk by causing inflammation in the body. Up to 25%Trusted Source of cancer causes may include infections and inflammation.
  • The article erroneously states that those with the EM rash are more likely to have a more “developed” form of Lyme.  In fact, I would state it’s probably just the opposite.
  • The article further erroneously states 10-14 days of doxycycline is the treatment, which case after case and study after study has proven this to be insufficient.
  • The article also erroneously states 70-80% get the EM rash when in fact the percentages are highly variable and many never get a rash at all.
  • Some with leukemia develop a skin rash that is different than the EM rash.  See top link for pictures of both.