Albumin: A Marker of Nutrition and Liver Health

What Is Albumin and Why Is It Tested

Albumin is the main protein found in the blood, produced by the liver. It makes up about 55–60% of all proteins in blood plasma. Albumin performs several important functions: it maintains oncotic (colloid osmotic) pressure, which prevents fluid from leaking out of blood vessels into tissues; it transports hormones, medications, fatty acids, and bilirubin; and it acts as an antioxidant. An albumin test helps evaluate liver function, nutritional status, and overall health.

Reference Ranges

The normal albumin concentration in adults is 3.5–5.0 g/dL (or 35–50 g/L). Slightly lower values may be normal in older adults. Laboratories provide their own reference ranges, which may vary slightly depending on the testing method used.

Why Albumin May Be Elevated

Elevated albumin is a fairly rare finding and most commonly indicates dehydration — when the body has less fluid, the blood becomes more concentrated and albumin values appear higher. True hyperalbuminemia is very uncommon. If albumin is above the normal range, it is worth first considering whether dehydration was present at the time of testing — perhaps fluid intake was insufficient, or diarrhea or vomiting had occurred.

Why Albumin May Be Low

Low albumin (hypoalbuminemia) has many possible causes. Liver diseases (cirrhosis, hepatitis) reduce albumin production. Kidney diseases (nephrotic syndrome) cause albumin to be lost through the urine. Chronic inflammatory conditions, infections, and sepsis redirect the liver away from albumin production toward making inflammatory proteins. Nutritional deficiency, especially a lack of protein, also lowers albumin levels. Other contributing factors include gastrointestinal diseases with malabsorption, pregnancy, burn injuries, and prolonged immobility.

What to Do With Your Result

If albumin is low, your doctor will likely assess liver function (ALT, AST, bilirubin), kidney function (creatinine, eGFR, urine proteins), inflammatory markers (CRP, ESR), and nutritional status. Understanding the underlying cause is key — whether it is the liver, kidneys, inflammation, or diet. Do not rush to take protein supplements without medical guidance — if the cause is a disease, supplements alone will not resolve the problem.

Monitoring Over Time

Albumin changes slowly because its half-life is approximately 20 days. It therefore does not reflect sudden changes, but it is a good indicator of long-term nutritional status and liver function. Regular monitoring is meaningful for people with chronic liver or kidney disease, oncology patients, and older adults. QbiLabs allows you to track albumin trends alongside liver and inflammatory markers.

Questions for Your Doctor

1. Does my albumin level suggest a nutritional problem or another cause? 2. Should I have additional tests for my liver or kidneys? 3. Could my chronic condition be contributing to the low albumin? 4. How often should I repeat the albumin test?