AST/ALT Ratio Calculator
Calculate your AST to ALT ratio for liver function assessment
What is AST/ALT Ratio?
The AST/ALT ratio is a valuable marker for evaluating liver health and differentiating between various liver conditions. AST (Aspartate Aminotransferase) and ALT (Alanine Aminotransferase) are enzymes found primarily in liver cells that are released into the bloodstream when liver cells are damaged.
Normal Range
Ratio: 0.8 – 1.0
Indicates healthy liver function with minimal cellular damage
Elevated Range
Ratio: 1.0 – 2.0
May suggest various liver conditions requiring medical evaluation
High Range
Ratio: > 2.0
Often associated with alcoholic liver disease or cirrhosis
Clinical Significance
ALT Predominance (AST/ALT < 1.0): Often seen in viral hepatitis, drug-induced liver injury, and non-alcoholic fatty liver disease (NAFLD). ALT is more specific to the liver than AST.
AST Predominance (AST/ALT > 1.0): More commonly associated with alcoholic liver disease, cirrhosis, and muscle disorders. AST is found in multiple tissues including heart, muscle, and kidneys.
Factors Affecting AST/ALT Levels
- Alcohol consumption: Chronic alcohol use typically raises AST more than ALT
- Medications: Certain drugs can cause hepatotoxicity affecting enzyme levels
- Viral infections: Hepatitis viruses often elevate ALT more significantly
- Metabolic conditions: Diabetes and obesity can affect liver enzyme ratios
- Exercise: Intense physical activity may temporarily elevate AST levels
Normal Reference Values
AST Normal Range
Males: 10-40 IU/L
Females: 9-32 IU/L
ALT Normal Range
Males: 10-40 IU/L
Females: 7-35 IU/L
When to Seek Medical Attention
Contact your healthcare provider if you experience symptoms such as:
- Persistent fatigue or weakness
- Abdominal pain, especially in the upper right area
- Yellowing of skin or eyes (jaundice)
- Dark urine or pale stools
- Unexplained weight loss
- Nausea or vomiting
Scientific References
Nyblom, H., et al. (2004). The AST/ALT ratio as an indicator of cirrhosis in patients with PBC. Liver International, 24(4), 333-337.
Botros, M., & Sikaris, K. A. (2013). The de ritis ratio: the test of time. The Clinical Biochemist Reviews, 34(3), 117-130.
Giannini, E., et al. (2003). Liver enzyme alteration: a guide for clinicians. Canadian Medical Association Journal, 169(6), 543-544.
Pratt, D. S., & Kaplan, M. M. (2000). Evaluation of abnormal liver-enzyme results in asymptomatic patients. New England Journal of Medicine, 342(17), 1266-1271.
American Gastroenterological Association. (2002). Medical position statement: evaluation of liver chemistry tests. Gastroenterology, 123(4), 1364-1366.