Also seen on reports as: Alb, Plasma Albumin
What is Albumin?
Albumin is the main protein in human blood. It is made entirely by the liver and has two major jobs — keeping fluid inside the blood vessels (preventing leakage into tissues) and carrying many substances, including hormones, fatty acids, calcium, bilirubin, and many medications, around the body.
Because the liver makes albumin, the level in blood is one of the most useful markers of how well the liver is producing proteins over the medium-to-long term. Albumin also reflects nutritional status, fluid balance, and protein loss through the kidneys or gut.
The test is run on a small blood sample drawn from a vein. NABL-accredited Indian labs report albumin in grams per decilitre (g/dL).
Why doctors order it
Albumin is part of the standard Liver Function Test (LFT) panel and is also routinely included in basic health checks, pre-operative assessments, and follow-up of chronic illnesses. It is one of the markers used to grade chronic liver disease (Child-Pugh score) and to assess overall protein status.
Doctors commonly order albumin when they see leg or abdominal swelling, persistent unexplained tiredness, signs of chronic illness, suspected malnutrition, or kidney disease with protein loss in the urine. It is also part of antenatal panels and routine ICU monitoring.
In Indian practice, albumin is also commonly checked in the work-up of chronic infection (tuberculosis, HIV, chronic viral hepatitis), suspected protein-losing gut disease, and unexplained weight loss in older adults — particularly when nutritional intake is uncertain.
What the result means
A normal albumin generally suggests the liver is producing proteins adequately, the kidneys are not leaking large amounts of protein, and gut absorption is reasonable. Low albumin (hypoalbuminaemia) does not by itself diagnose any single disease — it is a general signal that something is wrong, and the doctor uses the rest of the picture to find what.
The most common causes of low albumin seen in Indian practice include chronic liver disease (the liver is making less), nephrotic syndrome and other kidney conditions (the kidneys are losing albumin into the urine), severe acute illness or sepsis (capillary leak), chronic inflammation, and undernutrition with low protein intake. Acute illness — including any major infection or hospitalisation — can drop albumin temporarily even when the liver is fine.
Albumin tends to change slowly because its half-life in the body is about 20 days. So it is a better indicator of medium-term protein status than of acute change. A single low reading in someone who is unwell often recovers as the underlying illness improves.
Reference range
Values in g/dL — non-pregnant adult ranges
- Typical adult range
- Roughly 3.4 – 5.4 g/dL
- Mild hypoalbuminaemia
- Roughly 3.0 – 3.4 g/dL — check the cause, often improves with underlying illness
- Moderate
- Roughly 2.5 – 3.0 g/dL — usually significant; needs investigation
- Severe
- Below 2.5 g/dL — usually causes swelling and warrants urgent evaluation
- Pregnancy
- Naturally lower than non-pregnant range — fluid expansion dilutes the value
Pregnancy lowers albumin by ~5–10% because plasma volume expands. Acute illness temporarily lowers albumin even when the liver is fine. Albumin changes slowly (half-life ~20 days); single readings should be interpreted alongside the clinical picture.
Common factors that affect the result
Acute illness, sepsis, major burns, and major surgery all lower albumin temporarily — this is from a mix of capillary leak (albumin moves out of blood vessels into tissues) and the body's acute inflammatory response. The drop often recovers as the underlying illness resolves.
Pregnancy lowers albumin by 5–10% from baseline because the blood volume expands — this is a dilution effect, not a problem with liver protein production. Pregnancy-specific reference ranges apply.
Hydration status affects the apparent level — dehydration can falsely raise albumin (concentration effect), and rapid IV fluid administration can falsely lower it (dilution effect). Doctors interpret the value in context of fluid balance, particularly in hospitalised patients.
Common Indian dietary patterns — particularly very low-protein vegetarian diets in older adults, or in people undergoing significant restrictive eating — can lower albumin over weeks to months. Improving protein intake under dietary guidance is part of management when this is suspected.
When to talk to your doctor
- Your albumin is below the lab's lower limit, particularly if you have leg swelling, abdominal swelling, or unexplained weight changes.
- Your albumin is dropping over serial tests, especially alongside other LFT abnormalities or kidney findings.
- You have known chronic liver disease or chronic kidney disease and albumin is being tracked as part of monitoring.
- You are recovering from a serious illness or surgery and albumin is being followed alongside your nutritional and recovery plan.
- You are pregnant and your albumin is much lower than the lab's adult lower limit — your obstetrician will read the value against pregnancy-specific norms.
Related tests
Sources
- INASL Position Statements on Liver Function Test Interpretation — Indian National Association for Study of the Liver
- Indian Society of Nephrology — CKD Guidelines — Indian Society of Nephrology
- ICMR-NIN Indian Dietary Guidelines for Protein Intake — Indian Council of Medical Research — National Institute of Nutrition
- AASLD Guidelines on Chronic Liver Disease — American Association for the Study of Liver Diseases
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