Blood tests for liver health
For people with fatty liver disease (MASLD, formerly called NAFLD), alcohol-related liver disease or viral hepatitis, and people at higher risk of these.
12 tests explainedAI-verified against cited sources. Awaiting expert reviewLast reviewed 2026-10-19
Liver blood tests are often how a liver problem first comes to light, but they can stay in the usual range even when the liver is scarred. For fatty liver disease, guidelines use FIB-4, a score worked out from age, ALT, AST and platelets, to sort out who needs a closer look. Heart disease is one of the most common causes of death in people with fatty liver, so A1c and cholesterol are part of the picture too. CDC recommends hepatitis B and C tests for all adults at least once.
The tests that matter most
Most important first. Each one links to its full page, where the note for this group sits near the top.
Alanine Aminotransferase (ALT)
ALT is the most liver-specific of the liver enzymes, BSG notes. AASLD notes that the upper limits most labs print are higher than a true normal in fatty liver disease, and that ALT and AST are often in the usual range even with advanced scarring.
Sources: AASLD (2023) and British Society of Gastroenterology (2018)
- Men, 18+
- 0–44 U/L
- Women, 18+
- 0–32 U/L
Aspartate Aminotransferase (AST)
AST is read with ALT and goes into the FIB-4 score. BSG notes that an AST higher than ALT can point to advanced scarring, and that this ratio stays useful even when both are in the usual range.
- Men, 14+
- 8–48 U/L
- Women, 14+
- 8–43 U/L
FIB-4 Index
FIB-4 combines age, ALT, AST and platelets into one score for liver scarring (fibrosis). AASLD uses it as the first check in people with fatty liver or risk factors, and suggests repeating it every 1 to 2 years with prediabetes, type 2 diabetes or two or more metabolic risk factors. A higher score leads to a second test such as elastography or ELF.
Source: AASLD (2023)
- 18–64
- up to 1.3 index
- 65+
- up to 2 index
Platelet Count
Platelets are part of FIB-4. BSG notes that a low platelet count is the most common blood-count change in long-term liver disease and can be a sign of more advanced disease.
- Usual adult range
- 150–450 ×10³/µL
Gamma-Glutamyl Transferase (GGT)
GGT is most often raised by extra weight, alcohol or some medicines, so on its own it isn't specific to liver disease. BSG keeps it in the first liver panel because in fatty liver and alcohol-related liver disease it helps pick up cases that other liver tests can miss.
- Men, 18+
- 0–65 U/L
- Women, 18+
- 0–60 U/L
Alkaline Phosphatase (ALP)
ALP comes mainly from the bile ducts in the liver, and also from bone. BSG includes it in the standard first liver panel with bilirubin, albumin, ALT and GGT.
- Men, 19+
- 40–129 U/L
- Women, 17+
- 35–104 U/L
Bilirubin, Total
Bilirubin, albumin and the clotting test INR give information on how well the liver is working, BSG notes. A raised bilirubin on its own, with other liver tests in range, is most often Gilbert syndrome, an inherited trait that BSG says is not linked to liver disease or ill health.
- Usual adult range
- 0–1.2 mg/dL
Albumin
Albumin is made only by the liver, so it is part of the standard liver panel. BSG cautions that many other illnesses lower it too, so albumin alone isn't a reliable measure of how severe liver disease is.
- Usual adult range
- 3.5–5 g/dL
Hemoglobin A1c (HbA1c)
AASLD calls type 2 diabetes the risk factor with the most impact on fatty liver and on liver scarring getting worse. A1c is part of its first workup, and AASLD suggests that people with fatty liver be checked for diabetes.
Source: AASLD (2023)
- Usual adult range
- 4.8–5.6 %
LDL Cholesterol
Heart disease is one of the most common causes of death in people with fatty liver, and they are about twice as likely to have abnormal blood lipids. AASLD includes a fasting lipid panel in the first workup.
Source: AASLD (2023)
- Usual adult range
- up to 99 mg/dL
Hepatitis C Antibody
CDC recommends a hepatitis C test at least once for all adults 18 and older, and AASLD lists it in the fatty liver workup for anyone not tested before. A reactive antibody result is followed by an RNA test to see whether the virus is still there.
Sources: CDC (2025) and AASLD (2023)
Hepatitis B Surface Antigen (HBsAg)
CDC recommends that all adults 18 and older be tested for hepatitis B at least once, using three tests together: HBsAg, anti-HBs and total anti-HBc. BSG also includes HBsAg in the first checks for abnormal liver tests.
Sources: CDC (2023) and British Society of Gastroenterology (2018)
Ranges shown are the usual adult ranges labs print. The range on your own report is the one your result is judged against.
Getting results you can compare
- FIB-4 is less accurate under age 35, AASLD uses a different cutoff over age 65, and it shouldn't be used during an acute illness. Your clinician can tell you whether your score fits your age.
Source: AASLD (2023)
- AASLD advises that alcohol use be measured in everyone with fatty liver, including amount, pattern and how long. An honest account helps your clinician read your liver tests.
Source: AASLD (2023)
- When a liver test is out of range, BSG suggests looking for the cause rather than only repeating the same panel, unless a short-lived reason is likely.
Good to know
- Normal liver tests don't rule out liver scarring. AASLD says ALT and AST are frequently normal in people with advanced fatty liver disease, and BSG says normal liver blood tests do not rule out advanced fibrosis or cirrhosis.
Sources: AASLD (2023) and British Society of Gastroenterology (2018)
- AASLD notes that the ALT upper limits most labs print are higher than a true normal in fatty liver disease, which tops out around 29 to 33 U/L in men and 19 to 25 U/L in women. An ALT inside your lab's range can still be worth discussing.
Source: AASLD (2023)
- Fatty liver disease has new names. NAFLD is also called MASLD (metabolic dysfunction-associated steatotic liver disease), and NASH is also called MASH, so reports and articles may use either.
Source: NIDDK (2021)
Questions you could ask
- What does my FIB-4 score suggest for my age?
- Would a second test, such as elastography, add anything for me?
- How often should we recheck my liver tests and FIB-4?
- Have I been tested for hepatitis B and C?
- How does my alcohol use affect how you read my liver tests?
Sources
- AASLD Practice Guidance on the clinical assessment and management of nonalcoholic fatty liver disease, AASLD (2023)
- Guidelines on the management of abnormal liver blood tests, British Society of Gastroenterology (2018)
- Clinical Screening and Diagnosis for Hepatitis C, CDC (2025)
- Screening and Testing for Hepatitis B Virus Infection: CDC Recommendations, United States, 2023, CDC (2023)
- Diagnosis of NAFLD & NASH, NIDDK (2021)
AI-verified against cited sources. Awaiting expert review. Last reviewed 2026-10-19. How we build and check these pages.
Educational information, not medical advice. Blood Test Tracker doesn’t diagnose or treat, and it doesn’t replace your clinician. Talk with your clinician before changing medications, supplements or care.