Biomarker: Albumin, blood
Overview
Albumin, blood measures the concentration of albumin, a major protein made by the liver and circulating in the liquid (serum) portion of blood. Albumin helps maintain oncotic pressure so fluid stays within blood vessels and also binds and transports substances such as hormones, bilirubin, calcium, and many medicines. Low blood albumin levels (hypoalbuminemia) commonly indicate liver disease, kidney disease with protein loss, systemic inflammation, or poor protein/nutrient intake and absorption, and are linked to worse clinical outcomes. High albumin levels are less common and are usually associated with dehydration or hemoconcentration. Clinically, serum albumin is a routine marker of liver and kidney function, nutritional status, and overall disease severity and prognosis.
Clinical Use Cases
- Assess liver function and detect or monitor liver diseases such as hepatitis and cirrhosis.
- Evaluate kidney function, particularly conditions that cause protein loss in urine (nephrotic syndrome and other kidney diseases).
- Assess nutritional status and protein-energy malnutrition or malabsorption (for example, after weight‑loss surgery, celiac disease, Crohn disease, low‑protein diets).
- Monitor chronic or acute systemic illnesses where hypoalbuminemia reflects inflammation, disease severity, and prognosis.
- Part of a comprehensive metabolic panel (CMP) to evaluate general metabolic health.
- Help interpret fluid status, including edema, ascites, and risk of complications such as poor wound healing and postoperative morbidity.
- Monitor response to treatment for liver, kidney, or nutritional disorders by tracking changes in serum albumin.
Specimen Types
- Venous blood serum.
- Venous blood plasma.
Measurement Methods
- Automated colorimetric assays (for example, bromocresol green or bromocresol purple dye‑binding methods) on clinical chemistry analyzers.
- General clinical chemistry analyzer methods for serum or plasma albumin as specified in standard laboratory procedure manuals.
Test Preparation and Influencing Factors
- Usually no special preparation; fasting is not typically required for an albumin blood test.
- Hydration status: dehydration can increase measured albumin; overhydration or water intoxication can lower levels.
- Prolonged use of a tourniquet during blood draw may artifactually increase albumin because of hemoconcentration.
- High protein intake may contribute to higher albumin levels; chronic poor intake or malnutrition lowers levels.
- Gastrointestinal conditions causing malabsorption (such as celiac disease, Crohn disease, Whipple disease) can reduce albumin.
- Systemic inflammation and acute or chronic illness can lower albumin by altering distribution and synthesis; changes in albumin often parallel improvement or deterioration in clinical state.
- Liver diseases that impair synthesis and kidney diseases that increase urinary protein loss lower albumin.
Synonyms
- Serum albumin.
- Albumin blood test.
- ALB (test mnemonic/code).
- Albumin, serum.
This information is provided for general educational purposes and is not medical advice. Biomarker information may describe testing methods, measurements, or interpretations that vary by laboratory or specific test. For details about a particular lab test, including biomarkers measured, specimen type, collection requirements, preparation, and turnaround time, please refer to the individual test description. Talk with a licensed health care provider about your results.
