Main blood protein from the liver; reflects nutrition, inflammation, and fluid balance.
What it is
Albumin is the most abundant protein in plasma, synthesised by the liver. UK labs report serum albumin in g/L. Pathology Harmony adult bands are widely used. It maintains oncotic pressure (keeping fluid in blood vessels) and carries hormones, drugs, calcium, and fatty acids.
Albumin is synthesised only by the liver and has a half-life of about three weeks, so it falls slowly unless losses are large. It is a negative acute-phase reactant: inflammation lowers it.
Why it matters
Low albumin can accompany inflammation (negative acute-phase response), liver synthetic dysfunction, kidney protein loss (nephrotic states), gut loss, or poor intake over time. High albumin is uncommon and often reflects dehydration.
Trends with liver enzymes, CRP, and kidney tests matter more than one isolated value. Edema, unexplained weight change, or chronic illness with low albumin needs clinical review.
This guide is educational only and cannot diagnose you. Discuss results, especially anything outside your laboratory’s reference interval, or that does not match how you feel, with a GP or other appropriately qualified clinician.
How it affects the body
By holding fluid in the vascular space, albumin shapes blood volume and tissue oedema risk. As a carrier protein, low albumin alters free fractions of some hormones and medicines, one reason adjusted calcium is used when albumin is abnormal.
For athletes
Endurance athletes can see albumin dip with inflammation after ultras or with inadequate energy intake over long camps. Dehydration concentrates albumin. Persistent hypoalbuminaemia is not a “training adaptation”, get it reviewed, especially with swelling or heavy fatigue.
