Immunoglobulin G (IgG): what the amount of this antibody in the blood says
Immunoglobulin G, IgG for short, is an antibody: according to the NVKC, the Dutch society for clinical chemistry and laboratory medicine, a protein the body makes to clear away foreign substances and to fight infections with viruses, bacteria or parasites. According to the NVKC, specific white blood cells, the B cells, make these antibodies. According to the NVKC, in an infection IgM is often the first antibody produced, which is later replaced by IgG.
According to the NVKC, when all classes of immunoglobulins, IgG among them, are low, a person is very vulnerable to infections. According to the NVKC, a strong rise can occur in a serious infection, or when a group of cells has run out of control and makes too much of one or more immunoglobulins. Only a blood test shows how much IgG is in the blood.
For adults the NVKC uses a reference value for IgG of 7.0 to 16.0 g/l. Star-SHL gives 7 to 16 g/l for adults, Unilabs 7.00 to 16.00 g/l above age 16 and Diagnostiek voor U 6.5 to 16 g/L above age 15.
Turnaround up to 72 hours, estimate Turnaround: up to 72 hours after your blood draw (estimate).
According to the NVKC, immunoglobulin G (IgG) is an antibody that B cells make to clear away foreign substances and fight infections. For adults the NVKC uses a reference value for IgG of 7.0 to 16.0 g/l.
- Star-SHL gives 7 to 16 g/l for IgG in adults, Unilabs 7.00 to 16.00 g/l above age 16 and Diagnostiek voor U 6.5 to 16 g/L above age 15.
- According to the NVKC, a slight rise of the immunoglobulins, IgG among them, is common during or shortly after an infection.
- According to the NVKC, when all classes of immunoglobulins, IgG among them, are low, a person is very vulnerable to infections.
Reference Ranges
See the value that applies to you:
Choose male or female — this range differs by sex.
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This range also depends on context such as cycle phase or sample material; the highlighted rows apply to your group.
Reference values can vary between laboratories. Discuss your results with your GP for explanation and treatment decisions.
Immunoglobulin IgG: what Dutch laboratories use
These 3 laboratories publish the same value: 16 g/l.
| Laboratory | Group | Reference value (g/l) | Relative scale |
|---|---|---|---|
| Star-shl | · Everyone · 19 years and older | 7–16 g/l |
7 16
|
| Unilabs | · Everyone · 16 years and older | 7–16 g/l |
7 16
|
| Diagnostiek voor U | · Everyone · 16 years and older | 6.5–16.0 g/L |
6.5 16
|
Source: Star-shl
Source: Unilabs
Source: Diagnostiek voor U
Each value as the laboratory itself publishes it, retrieved in 2026.
Immunoglobulin IgG: what this test measures
The IgG test measures the amount of immunoglobulin G in the blood, in grams per litre (g/l), and according to the NVKC the immunoglobulin test distinguishes three kinds: IgA, IgG and IgM. Unilabs measures with nephelometry, according to MedlinePlus a lab test to measure the amount of immunoglobulins in the blood quickly and accurately. Star-SHL measures IgG turbidimetrically in serum.
Immunoglobulin IgG: why this value matters
According to the NVKC, an IgG measurement helps to check how the immune system functions and to find the cause of frequent infections. According to the NVKC, when the amount of each of the immunoglobulins is normal, the chance is small that frequent infections are caused by a lack of immunoglobulins.
Immunoglobulin IgG: how the blood test works
- Referral
- No GP referral needed. After the order we arrange the referral through ZorgDomein, within one business day; orders after 17:00 or at the weekend start on the next business day. ZorgDomein emails a barcode, and that barcode is what the draw site needs.
- The draw
- A blood draw from a vein in the arm, at a partner laboratory's draw site. No home kit, no finger prick.
- Results
- Turnaround: up to 72 hours after your blood draw (estimate).
- Where
- 650+ draw sites run by independent laboratories across the Netherlands. Draw sites
Immunoglobulin IgG: when is testing worthwhile?
According to the NVKC, the doctor can request an IgG test for symptoms of infections that occur frequently or keep coming back, and the test then covers IgA, IgG and IgM. According to the NVKC, this sometimes happens because a high total protein was found earlier, because according to the NVKC a high total protein concentration can come from one of the immunoglobulins being made in excess.
Immunoglobulin IgG: symptoms of a high or low value
Low Levels
According to MedlinePlus, a low IgG may be due to agammaglobulinemia (a very rare disorder with very low immunoglobulins), leukaemia (blood cancer), multiple myeloma (a type of bone marrow cancer), pre-eclampsia (high blood pressure during pregnancy) or treatment with certain chemotherapy. According to the NVKC, when all classes of immunoglobulins are low, the cause can lie in a disturbed production of white blood cells in the bone marrow. According to the NVKC, a low amount of immunoglobulins can also result from hereditary disorders, or from protein loss in the urine in kidney disease.
High Levels
According to the NVKC, a slight rise of the immunoglobulins, IgG among them, is common during or shortly after an infection. According to MedlinePlus, a raised IgG may be due to chronic infection or inflammation, hyperimmunization (a higher than normal number of specific antibodies), IgG multiple myeloma (a type of bone marrow cancer), liver disease or rheumatoid arthritis. According to the NVKC, with a strong rise further testing establishes which type of immunoglobulin is present in excess.
Immunoglobulin IgG: causes of a low or high value
What lowers the value
-
Disturbed production in the bone marrow
When all classes of immunoglobulins, IgG among them, are low, the cause can lie in a disturbed production of white blood cells in the bone marrow.
-
Hereditary disorders
A low amount of immunoglobulins, IgG among them, can result from hereditary disorders, which often becomes clear in childhood.
-
Protein loss in the urine from kidney disease
A low amount of immunoglobulins, IgG among them, can come from protein loss in the urine in kidney disease, and the kidneys then also lose many other proteins. Such protein loss can occur in advanced stages of diabetes, autoimmune diseases or chronic inflammation of the kidney.
-
Rarely
Agammaglobulinemia
A low IgG may be due to agammaglobulinemia, a very rare disorder with very low immunoglobulins.
-
Treatment with certain chemotherapy
MedlinePlus names treatment with certain chemotherapy medicines as one of the possible causes of a low IgG in the blood.
What raises the value
-
Infection
A slight rise of the immunoglobulins, IgG among them, is common during or shortly after an infection, and a strong rise can occur in a serious infection.
-
A group of cells running out of control
Sometimes a group of cells runs out of control and makes far too much of one kind of immunoglobulin, for example IgG, at the expense of other immunoglobulins.
-
Chronic infection or inflammation
MedlinePlus names chronic infection or inflammation as one of the possible causes of a raised IgG in the blood.
-
Liver disease
MedlinePlus names liver disease as one of the possible causes of a raised IgG in the blood.
-
Rheumatoid arthritis
MedlinePlus names rheumatoid arthritis as one of the possible causes of a raised IgG in the blood.
Immunoglobulin IgG: lifestyle and this value
Discuss an IgG result outside the reference value of the laboratory that tested the blood with your GP. According to MedlinePlus, normal values for IgG may vary slightly between laboratories.
Immunoglobulin IgG: frequently asked questions
Is IgG the same as IgM?
No, according to the NVKC IgG and IgM are different classes of immunoglobulins. In an infection IgM is often the first antibody produced, and according to the NVKC IgG is made in larger amounts or on a second contact with the antigen, the foreign substance.
Can IgG pass from mother to child?
According to the NVKC, IgG can reach the unborn child through the placenta of the pregnant woman, and it provides the baby's immune defence in the first six months.
Are IgG values different in children?
According to the NVKC, the reference values for immunoglobulins, IgG among them, depend on age. Diagnostiek voor U, for example, gives 5.2 to 15.6 g/L for IgG in children aged 6 to 15.
Immunoglobulin IgG: sources
- Star-shl, Labbepalingen (referentiewaarden per bepaling), star-shl.nl, geraadpleegd 2026-10-01 (retrieved 2026) star-shl.nl
- Unilabs, Bepalingenklapper (referentiewaarden per bepaling), bepalingenklapper.nl, geraadpleegd 2026-10-01 (retrieved 2026) bepalingenklapper.nl
- Diagnostiek voor U, eLabgids (Referentiewaarden DvU), diagnostiek.getincontrol.eu, geraadpleegd 2026-10-01 (retrieved 2026) diagnostiek.getincontrol.eu
- NVKC, Alles over testen: Immunoglobuline IgA IgG IgM, allesovertesten.nl, geraadpleegd 2026-10-16 (retrieved 2026) allesovertesten.nl
- MedlinePlus Medical Encyclopedia, Quantitative nephelometry test, medlineplus.gov, review date 2026-05-01, geraadpleegd 2026-10-16 (retrieved 2026) medlineplus.gov
Results without a doctor's assessment
You receive your values with the unit and reference range. A doctor's assessment is not part of this site. Discuss your results with your GP for explanation and treatment decisions.
Immunoglobulin IgG
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