Liver Function Test (LFT) Decoded: SGOT, SGPT, Bilirubin and What They Actually Measure
SGOT, SGPT, ALP, bilirubin — a liver function test bundles several different measurements together. Here's what each one actually tells you about liver health.
A liver function test (LFT) isn't one test — it's a panel of several markers that each measure a different aspect of how the liver is functioning, and reading them together matters more than reading any one in isolation.
The enzymes: SGOT and SGPT
SGOT (AST) and SGPT (ALT) are enzymes that leak into the bloodstream when liver cells are stressed or damaged. SGPT is considered more liver-specific; SGOT also appears when heart or muscle tissue is under stress, which is why the ratio between them (not just the raw numbers) is often more informative than either alone.
ALP and GGT: the "drainage" markers
Alkaline Phosphatase (ALP) and GGT rise more when there's an obstruction in bile flow rather than direct cell damage. A pattern of high ALP with normal SGOT/SGPT points somewhere different than the reverse pattern.
Bilirubin: direct vs. total
Bilirubin is a breakdown product of old red blood cells, processed by the liver. Total bilirubin is the headline number, but direct (conjugated) bilirubin specifically tells you whether the liver is processing it properly — an important distinction that a single "bilirubin high" flag glosses over.
Why one bad reading isn't a verdict
Alcohol, certain medications, a recent intense workout, or even a viral illness can transiently raise SGOT/SGPT without any lasting liver issue. What's actually informative is whether the elevation resolves on a repeat test a few weeks later, or persists.
This is general health information, not medical advice. Always talk to a qualified healthcare professional about your own results.
