Albumin
Albumin is the most abundant plasma protein. It carries hormones, drugs and calcium, and maintains osmotic pressure. Low albumin is a sensitive marker of liver synthesis, malnutrition and chronic illness.
What it measures
Albumin is produced exclusively by the liver and accounts for over half of plasma protein. It performs two main jobs: carrying hydrophobic molecules (steroid hormones, free fatty acids, bilirubin, many medications, half of plasma calcium) and pulling water into the vascular space (oncotic pressure). Its 21-day half-life means albumin reflects sustained synthesis and loss rather than today's snapshot, making it a slow but reliable marker of chronic liver health and nutritional status. Albumin also matters because a low value drops both total calcium and the free fraction of many drugs — labs often report a calcium corrected for albumin.
What a high value can mean
- Dehydration — concentrates the protein.
- Rarely an isolated finding without dehydration.
What a low value can mean
- Liver synthesis failure — cirrhosis, end-stage liver disease.
- Chronic inflammation — interleukin-6 suppresses albumin production (an inverse acute-phase reactant).
- Malnutrition, malabsorption — though albumin is too slow to reflect short-term status.
- Protein-losing kidney disease (nephrotic syndrome) — urine dipstick will show ≥3+ protein.
- Protein-losing enteropathy — much less common.
- Severe burns, large wounds — protein leak.
- Pregnancy, fluid overload, multiple myeloma — dilutional or competitive.
When to discuss with a doctor
Albumin <3.0 g/dL warrants identifying the cause: urine protein/creatinine ratio (rule out nephrotic syndrome), liver panel (synthesis function), nutritional history. Acute drop alongside oedema is suspicious for nephrotic syndrome. Mediora.AI uses albumin to correct calcium in the report and flags the synthetic-failure pattern when paired with elevated bilirubin and low platelets.