IgM (immunoglobulin M)
IgM is the first antibody produced with a new infection. Serum IgM is part of the assessment of humoral immunity.
| Rating | Range | What it means |
|---|---|---|
| Worth improving | below 0.4 g/L | Low IgM — often not significant; if you have symptoms, part of an immune workup. |
| Good | 0.4 – 2.3 g/L | IgM within range. |
| Worth improving | 2.3 g/L and above | Elevated IgM — often an acute infection. |
Why it matters
Elevated often means an acute/recent infection.
If it’s low
Low IgM is often of no significance; with symptoms it can be part of an immune deficiency.
If it’s high
Elevated IgM often accompanies an acute infection; a persistent rise less often indicates special (lymphoproliferative) disorders (consultation).
What to do
Evaluate together with IgG/IgA and symptoms; a single value is not a diagnosis.
When to see a doctor
Persistent marked abnormality with symptoms → immunologist.
Read together with
IgG (immunoglobulin G) · IgA (immunoglobulin A)
This content is for information only and is not a substitute for medical advice. Talk to your doctor about your results.
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