Liver Function Test Results Explained: ALT, AST, Bilirubin

A liver function test (LFT) is a group of blood tests that show how your liver is working. ALT (also called SGPT) and AST (SGOT) are enzymes that rise when liver cells are irritated; ALP and GGT relate to the bile ducts; bilirubin and albumin show how well the liver clears waste and makes protein. Mildly raised enzymes are common and often linked to fatty liver.

Paste your LFT into the free Liver Function Test Checker to see each result explained. It understands the older names, SGPT and SGOT, and runs privately in your browser.

What does each liver test measure?

Test	What it shows	Typical adult range
ALT (SGPT)	Enzyme mainly in liver cells	Men 7–55 U/L, women 7–45 U/L
AST (SGOT)	Enzyme in liver, heart and muscle	8–48 U/L
ALP	Enzyme in bile ducts and bone	40–129 U/L
GGT	Bile-duct enzyme, raised by alcohol	Men 8–61 U/L, women 5–36 U/L
Total bilirubin	Yellow breakdown product of red cells	0.1–1.2 mg/dL (about 2–21 µmol/L)
Direct bilirubin	Bilirubin processed by the liver	0–0.3 mg/dL (0–5 µmol/L)
Albumin	Main protein made by the liver	3.5–5.0 g/dL (35–50 g/L)
Total protein	Albumin plus globulins	6.0–8.3 g/dL
INR	How fast blood clots	0.8–1.2 (higher on blood thinners)

Ranges differ between labs, so compare with your own report. To convert bilirubin from mg/dL to µmol/L, multiply by 17.1.

What do raised liver enzymes mean?

ALT and AST rise when liver cells are irritated. The most common reason today is fatty liver disease (now often called MASLD), linked to extra weight around the waist, diabetes and high triglycerides. Other common causes are alcohol, viral hepatitis, some medicines (including high doses of paracetamol, some antibiotics, statins in a few people) and herbal or bodybuilding supplements. AST can also rise after hard exercise because it's found in muscle.

ALP and GGT tend to rise when bile flow is blocked, for example by gallstones. ALP also comes from bone, so it's naturally higher in teenagers and in pregnancy. GGT rises with regular alcohol use and some medicines.

Bilirubin above the range can cause yellow skin or eyes (jaundice). A mildly raised indirect bilirubin with normal enzymes is often Gilbert's syndrome, a harmless inherited trait that becomes more noticeable when fasting or ill.

Low albumin can reflect long-term liver disease, kidney protein loss, poor nutrition or inflammation. A high INR in someone not on blood thinners can mean the liver isn't making enough clotting proteins.

How do I check my liver function test?

1. Open the Liver Function Test Checker.
2. Paste the report text, upload a digital PDF, or choose Enter values and type ALT, AST, ALP, GGT, bilirubin and albumin.
3. Set sex and age, since some ranges differ for men and women.
4. Read the status, explanation and doctor questions for each line. A warning appears if any value is far outside the usual range.

How can I look after my liver?

For fatty liver, the evidence points to gradual weight loss (7–10% of body weight can make a big difference), regular activity, fewer sugary drinks and refined carbs, more vegetables, beans and whole grains, and little or no alcohol. Our Fatty Liver Diet Plan turns these into a weekly menu, and the BMI Calculator helps you track progress. Check with your doctor before taking herbal "liver detox" products, as some can harm the liver.

When should I see a doctor urgently?

Seek prompt care for yellow eyes or skin, dark urine with pale stools, severe pain in the upper right abdomen, vomiting blood, confusion or unusual drowsiness, or very high enzyme levels. The checker flags results far outside the usual range.

Learn more in how to read a blood test report, or check your liver results now.