In this Article

• Introduction to liver blood test
• What are the aminotransferases?
• Normally, where are the aminotransferases?
• What are normal levels of AST and ALT?
• What do elevated AST and ALT mean?
• What liver diseases cause abnormal aminotransferase levels?
• What medications cause abnormal aminotransferase levels?
• What are less common causes of abnormal aminotransferase levels?
• How are healthy people evaluated for mild to moderate rises in aminotransferase levels?
• How about monitoring aminotransferase levels?
• What about other liver enzymes?
• Patient Discussions: Liver Blood Tests - Helped With Your Diagnosis
• Liver Blood Tests Index

What are normal levels of AST and ALT?

The normal range of values for AST (SGOT) is from 5 to 40 units per liter of serum (the liquid part of the blood).

The normal range of values for ALT (SGPT) is from 7 to 56 units per liter of serum.

What do elevated AST and ALT mean?

AST (SGOT) and ALT (SGPT) are sensitive indicators of liver damage or injury from different types of disease. But it must be emphasized that higher-than-normal levels of these liver enzymes should not be automatically equated with liver disease. They may mean liver problems or they may not. For example, elevations of these enzymes can occur with muscle damage. The interpretation of elevated AST and ALT levels depends upon the entire clinical evaluation of a patient, and so it is best done by doctors experienced in evaluating liver disease.

The precise levels of these enzymes do not correlate well with the extent of liver damage or the prognosis (outlook). Thus, the exact levels of AST (SGOT) and ALT (SGPT) cannot be used to determine the degree of liver disease or predict the future. For example, patients with acute viral hepatitis A may develop very high AST and ALT levels (sometimes in the thousands of units/liter range). But most patients with acute viral hepatitis A recover fully without residual liver disease. For a contrasting example, patients with chronic hepatitis C infection typically have only a little elevation in their AST and ALT levels. Some of these patients may have quietly developed chronic liver disease such as chronic hepatitis and cirrhosis (advanced scarring of the liver).

It is, therefore, worth mentioning that these liver enzymes do not give an indication of the function of the liver. Sometimes they are mistakenly referred to as “liver function tests” or LFTs, but it is a misnomer commonly used.

Liver Blood Tests - Helped With Your Diagnosis

The MedicineNet physician editors ask:

Please describe how Liver Blood Tests has helped in your diagnosis.

Comment submissions for this question have ended.
See 20 Viewer Comments

View Comments

Suggested Reading by Our Doctors

• ibuprofen, Advil, Children's Advil/Motrin, Medipren, Motrin, Nuprin, PediaCare Fever, etc. - Explains the medication ibuprofen (Advil, Motrin, Nuprin, Medipren) a drug used for the management of mild to moderate pain, fever, and inflammation. Article includes descriptions, uses, drug interactions, and side effects.
• CT Scan (Computerized Axial Tomography) - CT Scan (Computerized Axial Tomography, CAT scan) is a procedure that assists in diagnosing tumors, fractures, bony structures, and infections in the organs and tissues of the body.
• Abdominal Pain - Learn about abdominal pain (pain in the stomach / abdomen) including causes, symptoms, how abdominal pain is diagnosed, and how abdominal pain is treated.

Read more Liver Blood Tests related articles »

Latest Medical News

• Patients Not Always Told of Lab Results
• Drug May Be Dangerous for Kids With Graves' Disease
• Hispanics Respond Poorly to Standard Hepatitis C Therapy