IgM

ChemistryAlso known as: Immunoglobulin m

Measures IgM antibodies in blood, indicating acute immune response.

Normal Range
40 – 230 mg/dL
mg/dL
Abnormal Levels
Consult your provider
Specimen Type
Blood

Why This Biomarker Matters

Elevated IgM typically signals a recent or active infection. Detecting IgM helps distinguish new infections from past immunity and guides appropriate clinical management.

Understanding Your Results

Normal Range

40 – 230 mg/dL

Overview

Immunoglobulin M (IgM) is an antibody produced by your immune system, typically in response to acute infections. IgM appears early during infection before IgG antibodies develop, making it useful for detecting recent or active infections. Elevated IgM levels can indicate acute viral infections (like flu or COVID-19), bacterial infections, autoimmune diseases, or other immune system problems. IgM is the largest antibody and provides the first line of immune defense.

Research & Evidence

100 publications

Sort:
Clinical Profile and Outcome of Children with Scrub typhus: A Tertiary Care Centre Observation.
J Trop Pediatr · 2026
PMID: 41968754
An observational study on lupus nephritis combined with cryoglobulinemia.
Ren Fail · 2026
PMID: 41943594
Development of clinical manifestations in individuals positive for antiphospholipid antibodies according to the 2023 ACR/EULAR serological domains.
Semin Arthritis Rheum · 2026
PMID: 41763087
Leptospirosis: Unveiling the Hidden Threat in a Non-Endemic Region of India.
Trop Med Int Health · 2026
PMID: 41665288
Newborn IgG and IgM antibodies to maternal SARS-CoV-2 infection in pregnancy and child neurodevelopmental outcomes.
Brain Behav Immun · 2026
PMID: 41956300
New advances in the diagnosis and pathologic spectrum of monoclonal gammopathy of renal significance.
Curr Opin Nephrol Hypertens · 2026
PMID: 41883004
A Case of IgM Pemphigoid Suggesting Possible Transition to IgG Mucous Membrane Pemphigoid.
J Dermatol · 2026
PMID: 41947322
IgM nephropathy is a controversial entity: a distinct nephropathy or part of the podocytopathy spectrum? A systematic review of the literature.
BMC Nephrol · 2026
PMID: 41981519
Host natural IgM shapes systemic efficacy of the oncolytic adenovirus.
Mol Ther · 2026
PMID: 41962544
Low IgM Levels in Adult IEI: Classification Challenges and Clinical Implications.
J Clin Immunol · 2026
PMID: 41979700

Research data from MEDLINE/PubMed · 100 articles

Technical Information (LOINC Codes)

Standardized laboratory codes for this biomarker

2472-9Primary
IgM [Mass/volume] in Serum or Plasma
mg/dL
14002-0
IgM [Units/volume] in Cord blood
[arb'U]/mL
6783-5
IgM [Mass/volume] in Urine by Electrophoresis
g/L
44600-5
IgM [Presence] in 24 hour Urine by Immunofixation
15185-2
IgM [Mass/volume] in Body fluid
mg/dL
18304-6
IgM [Presence] in Urine by Immunofixation
18303-8
IgM [Presence] in Serum by Immunofixation
6784-3
IgM [Mass/volume] in Urine by Immunoassay
mg/dL
26958-9
IgM [Mass/volume] in 24 hour Urine
mg/dL
15186-0
IgM [Presence] in Serum by Immunoelectrophoresis
17009-2
IgM [Presence] in Serum
2471-1
IgM [Mass/volume] in Cerebral spinal fluid
mg/dL
76491-0
IgM [Moles/volume] in Serum or Plasma
umol/L
21351-2
IgM [Presence] in Cerebral spinal fluid by Immunofixation
25446-6
IgM [Presence] in Urine by Immunoelectrophoresis
30142-4
IgM [Presence] in 24 hour Urine by Immunoelectrophoresis
50992-7
IgM [Mass/volume] in Cord blood
mg/dL
54902-2
IgM [Mass/volume] in Peritoneal fluid
g/L
55925-2
IgM [Mass/volume] in Serum by Electrophoresis
g/L
56123-3
IgM [Mass/volume] in Urine
mg/dL
58764-2
IgM [Mass/time] in 24 hour Urine
mg/(24.h)
106812-1
IgM [Mass/volume] in Cord blood by Immunoassay
g/L

Available Lab Tests

Order tests that measure this biomarker

IgM Test

$24.54