Albumin/Globulin (A/G) Ratio
A calculated comparison of two groups of blood proteins, albumin and globulins. It is one clue about the liver, kidneys and immune system.
AI-verified against cited sources. Awaiting expert reviewAlso called A/G, AGR, A/G ratioLOINC 1759-0
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What it is
Blood proteins come in two big groups. Albumin is made by the liver and keeps fluid inside blood vessels. Globulins include antibodies and carrier proteins, and are made by the liver and by immune cells. The A/G ratio is albumin divided by globulin. Globulin is usually worked out by subtracting albumin from total protein, so labs can print the ratio without any extra blood test.
Why it matters
The ratio shows whether the balance between these two protein groups has shifted. Albumin is usually higher than globulin, so the ratio is usually above 1. A low ratio can come from lower albumin, higher globulin or both, and a high ratio usually means globulin is low. The ratio alone doesn't say which protein changed or why, so clinicians read it together with albumin, globulin and total protein.
If it’s low
A low ratio means albumin is low, globulin is high, or both. It is more common than a high ratio and has many ordinary explanations, such as inflammation or pregnancy. A clinician can tell which protein is driving it by looking at albumin and globulin.
Common causes
- Pregnancy, when a lower albumin level is normal
- Infection or inflammation, when albumin falls and antibody-type proteins rise
- Autoimmune conditions such as lupus or rheumatoid arthritis
- Liver disease, including cirrhosis
- Kidney disease that leaks protein into the urine
- Poor nutrition or poor absorption of nutrients
- Blood disorders that raise globulins, such as multiple myeloma, which are less common
What can help
- Work with your clinician to find and treat the underlying cause
- Ask whether albumin, total protein, urine protein or a protein electrophoresis test would help explain it
- Mention swelling, tiredness, weight loss or yellow skin or eyes
If it’s high
A high ratio means albumin is high compared with globulin, usually because globulin is low. It is uncommon, and it gets most of its meaning from the globulin result and your health history.
Common causes
- Normal variation, since about 1 in 20 healthy people fall outside a standard reference range
- Low globulin levels, for example when the body makes fewer antibodies
- Certain inherited (genetic) conditions
- Leukemia, which is a less common cause
What can help
- Ask your clinician to look at albumin, globulin and total protein together
- Ask whether a protein electrophoresis test would add useful information
Usual ranges
What labs print as the reference range, by who was tested. Ranges differ a little between labs, so the range on your own report is the one your result is judged against.
See A/G ratio by age and sex, with the U.S. survey numbers where they exist.
How common is your level?
NHANES describes the US civilian, non-institutionalized population, not a 'healthy' reference group. People with disease, on medication, fasting or not (except fasting-subsample markers), smokers and so on are all included. A percentile says where a value sits among Americans of that sex and age, not whether it is normal.
Use the left and right arrow keys to read each age. Shift moves five years.
Reference data derived from CDC/NCHS National Health and Nutrition Examination Survey (NHANES), cycles 2015-2016, 2017-March 2020 (pre-pandemic), August 2021-August 2023. Analysis by bloodtesttracker.com; not endorsed by CDC, NCHS or HHS.
Explore A/G ratio by age and sex: every percentile as a table, with a download.
What can affect your result
- Everything that moves albumin: inflammation, hydration, posture, pregnancy and some medicines
- Anything that moves globulins: infections, autoimmune conditions and some blood disorders
- Age: Labcorp uses a wider, higher range for babies and young children
- Method: the albumin dye method, and whether the ratio is calculated or taken from electrophoresis
- Anything that changes albumin or total protein also changes the ratio, including dehydration, posture, inflammation and pregnancy.
- Globulin is worked out as total protein minus albumin, so an error in either measurement carries into the ratio.
- Different albumin dye methods (bromocresol green versus purple) can shift albumin, and so the ratio, slightly.
- A ratio built from protein electrophoresis fractions is not exactly the same as the usual calculated one.
Follows albumin and globulin. Changes usually take weeks, since albumin lasts about 2 to 3 weeks in the blood, but it can move within days during an acute illness.
When to talk to a clinician
Contact a clinician soon if your ratio is outside your lab's range along with swelling in the legs, face or belly, yellow skin or eyes, fevers or night sweats that don't go away, bone pain, or unexplained weight loss. A small shift with no symptoms can usually wait for your next visit, where your clinician can look at albumin and globulin together.
Questions you could ask
- How does my ratio compare with my earlier results?
- Is my globulin level low, and does it need any follow-up?
- Is the low ratio from low albumin, high globulin, or both?
- Would a protein electrophoresis or urine protein test add useful information?
Questions people ask
Is the A/G ratio a separate blood test?
No. It is calculated from your albumin and total protein results, which are already part of a routine metabolic panel. Globulin is total protein minus albumin, and the ratio is albumin divided by globulin.
My ratio is slightly out of range but my albumin and total protein look fine. Should I worry?
A small shift is common. About 1 in 20 healthy people fall outside a standard reference range, and the ratio moves when either albumin or globulin changes a little. Bring it up with your clinician, who can look at the pieces and your symptoms.
Does a low A/G ratio mean cancer or liver disease?
Not by itself. Inflammation, infection, pregnancy, autoimmune conditions, and liver or kidney problems can all lower the ratio, and most of these are far more common than cancer. One large study did link very low ratios to more cancer and deaths, but it needs confirmation. Your clinician can put your result in context.
Show the science and sources
For clinicians and researchers
A/G = albumin / globulin, with globulin = total protein - albumin, so the ratio is unitless and both values must share a unit. Some labs derive it from electrophoresis fractions instead (LOINC 44429-9). A low ratio reflects hypoalbuminemia (inflammation, hepatic synthetic failure, nephrotic syndrome, protein-losing enteropathy) or hyperglobulinemia (polyclonal gammopathy from chronic infection, inflammation, autoimmune or liver disease, or a monoclonal protein such as myeloma). A high ratio usually reflects hypogammaglobulinemia. The ratio is a derived value that adds little beyond its components, and when the globulin fraction is high, serum protein electrophoresis separates a polyclonal from a monoclonal pattern. Reference intervals are lab- and method-specific. Low pretreatment A/G ratio is associated with poorer survival in a pooled analysis of 28 cancer studies, and a Korean cohort of 26,974 checkup attendees found adjusted hazard ratios of 2.69 (ratio 1.0-1.1) and 6.71 (ratio under 1.0) for all-cause mortality versus ratios of 1.5 or higher; this is observational and needs replication.
LOINC 1759-0 (primary), 44429-9. Specimen: calculated.
Sources
- Pediatric Testing Reference Ranges (A/G Ratio, result 012047), Labcorp
- Comp. Metabolic Panel (14) (test 322000), sample patient report, Labcorp
- Comprehensive Metabolic Panel (test code 10231): lists Globulin (calculated) and Albumin/Globulin Ratio (calculated), and describes total protein as the sum of albumin and globulins, Quest Diagnostics
- Total Protein and Albumin-Globulin (A/G) Ratio (MedlinePlus Lab Tests), MedlinePlus, National Library of Medicine
- Low albumin-to-globulin ratio associated with cancer incidence and mortality in generally healthy adults, Annals of Oncology (2014)
- Pretreatment albumin to globulin ratio can serve as a prognostic marker in human cancers: a meta-analysis, Clinica Chimica Acta (2018)
- LOINC codes for albumin/globulin ratio (NLM Clinical Tables search), National Library of Medicine
AI-verified against cited sources. Awaiting expert review. Last reviewed 2026-10-03. How we build and check these pages.