Immunoglobulin M Test (IgM Test)

The Immunoglobulin M (IgM) test is a blood test that measures the level of IgM antibodies in the bloodstream. IgM is one of the five types of antibodies produced by the immune system in response to an infection.

The IgM test is often used to diagnose acute infections or recent exposure to an infectious agent. High levels of IgM antibodies in the blood indicate that the person has recently been infected with a specific virus or bacteria. The test is commonly used to diagnose viral infections such as hepatitis A, B, and C, measles, and rubella.

The IgM test is also used to screen for autoimmune diseases such as lupus and rheumatoid arthritis. In these cases, the test helps to detect the presence of autoantibodies, which are antibodies that mistakenly attack the body's own tissues.

The IgM test is a simple blood test that can be done in a laboratory or doctor's office. There is no special preparation needed for the test. The results of the test are usually available within a few days.

It is important to note that a positive IgM test does not necessarily mean that the person has an active infection. IgM antibodies can remain in the bloodstream for several weeks or even months after an infection has cleared. Therefore, the test results should be interpreted in conjunction with the person's symptoms, medical history, and other laboratory tests.