Understanding the SGPT Blood Test

Page content

How Is The Test Performed?

The SGPT blood test is performed by drawing a sample of blood. Unlike other similar tests, the patient does not need to fast and there is no special preparation needed. If additional tests are being performed though, the patient should check with the healthcare provider to see if there are any precautions that they should take. Blood is typically drawn from a vein in the arm at the physician’s office or healthcare clinic per the physician’s request.

What Is The Test Used For?

The SGPT test is most commonly ordered to check for problems of the liver. Alanine aminotransferase is an enzyme present in the liver and kidney cells. While it is also found any smaller amounts elsewhere in the body, abnormal levels of this enzyme can detect damage, disease, or disorder of the liver. Unlike other signs and symptoms that may present themselves as a liver condition worsens, the levels of ALT are useful in determining liver problems earlier on. However, the SGPT is specifically useful for detecting liver conditions associated with drugs, toxins, and hepatitis. It is also important to note that abnormal ALT levels can also be a result of health conditions that are not related to the liver.

SGPT Blood Test Results

Normal results may vary from one laboratory to the next and there are considerable variances in the ranges. According to the Saint Vincent Catholic Medical Centers in New York, normal SGPT results will be between 4-36 units per liter or 0.07-0.62 microKat/L. ALT levels not falling within this range can be considered abnormal based on this criteria. Levels that are too high can be indicative of an underlying health condition. The patient should also keep in mind that certain things can alter the results of the SGPT test. Large meals, particularly those high in fat, strenuous physical activity, and some injectable medications can cause an increase in ALT levels. If this is the case, levels should return to normal soon and the test can be repeated. The patient should make the physician aware of any medications, prescription or over the counter that they may be taking as well.

Other Useful Information

The SGPT test may not be strictly used to determine if the individual has sustained liver damage due to toxins, drugs, and hepatitis. Those who must take prescription drugs that can damage the liver, who have a significant family history of liver problems, diabetics, and patients undergoing treatment for liver problems may also commonly have this test ordered. In addition to checking ALT levels, the physician may also order an AST, ALP, GGT, and other tests related to the liver.


ALT. Lab Tests Online. 2001-2010 American Association of Clinical Chemistry. Modified 23, February 2010. Viewed 23, February 2010. https://www.labtestsonline.org/understanding/analytes/alt/glance.html.

Alanine Aminotransferase (ALT). Essiq, Maria. MS, ELS. New York Health-Saint Vincent Catholic Medical Center. 2, January 2008. Viewed 23, February 2010. https://www.svcmc.org/1415.cfm.