Albumin

Albumin is the main protein circulating in your blood, produced by the liver. It helps hold fluid inside the blood vessels and transports hormones, vitamins and other substances around the body.

It matters because albumin reflects both liver function and overall nutritional and general health, and it tends to fall with age, chronic illness and inflammation. That link to overall condition is why it features in blood-based biological-age scores.

In practice, albumin is read as part of a liver panel and interpreted alongside the other markers; a low level is a non-specific signal that prompts a wider look rather than a diagnosis in itself.