Skip to content
Missed Black Friday? Check out our HUGE offers for Christmas!
Missed Black Friday? Check out our HUGE offers for Christmas!

Immunoglobulin M (IgM) - description and reference ranges

What is it?

Immunoglobulin M (IgM) is an antibody blood protein. IgM is the largest antibody, and it is the first antibody to appear in the response to initial exposure to infection/antigen.

Reference ranges

If your indicative IgM level is lower than the reference range for our laboratory:

An IgM deficiency is a health condition where your body does not make enough Immunoglobulin M (IgM). People with IgM deficiency are more likely to get infections or not be able to fight them off very easily or quickly.

You can discuss this result with your GP if you are concerned.

If your indicative IgM level is higher than the reference range for our laboratory:

High levels of IgM generally implies that you have an infection or an inflammatory or autoimmune disease. This also generally involves your central nervous system. In cases of an autoimmune disorder, this causes your immune system to attack your own healthy cells by mistake. This can lead to various problems with health.

You can discuss this result with your GP if you are concerned.

Quick test finder

Quick test finder

Find what you need in under 30 seconds with our (very clever!) test finder. We offer a huge range of markers all a few clicks away, as well as fastest turnaround times.

Find your test

You might also like to read

  • The PSA Blood Test and Prostate Cancer Screening
    Adam Staten

    The PSA Blood Test and Prostate Cancer Screening

    In the UK, we screen for many different conditions. This starts before we are even born when foetuses are screened for conditions such as Down’s syndrome then, in the new born period, babies are screened for metabolic diseases and hearing problems, school children are screened for colour blindness, and in adulthood we are screened for breast cancer, cervical cancer, and bowel cancer. But we don’t screen for prostate cancer despite the existence of a simple blood test that can alert us to the possibility of the disease.

    Why not?

    Read now
  • Dr Mike Forsythe on Vitamin B12
    Dr Mike Forsythe

    Dr Mike Forsythe on Vitamin B12

    Vitamin B12, also known as cobalamin, is a unique nutrient, as it’s the only vitamin we require that must be sourced externally from animal-derived foods or supplements. So how do we know if we are getting enough of it? What...

    Read now