Also known as: Serum glutamic-pyruvic transaminase (SGPT)
Name: Alanine aminotransferase
Related tests: ALP, AST, Bilirubin, Liver panel
Why is the test done?
To assess liver damage.
When is the test done?
If your doctor thinks you have symptoms suggesting liver problems.
What samples are required?
A blood sample taken from a vein in the arm.
What is being analysed?
ALT is an enzyme found mainly in the liver; small amounts are found in the kidneys, heart and muscles. Normally, blood ALT levels are low. When the liver is damaged, ALT is released into the blood, usually before more obvious signs of liver damage, such as jaundice (yellow skin and eyes), appear.
How is it used?
When is it requested?
What does the test result mean?
Is there anything else I should know?
How is it used?
ALT is used to assess liver damage. ALT values are usually compared with those of other enzymes, such as alkaline phosphatase (ALP) and aspartate aminotransferase (AST), to assess what type of liver disease is present.
When is it requested?
Doctors request ALT (and many other tests) to assess patients with symptoms of liver disease. Some of these symptoms include jaundice (yellow eyes and skin), dark urine, nausea, vomiting, abdominal swelling, usually weight gain, and abdominal pain.
ALT may be requested on its own or together with other tests for: people who have been exposed to the hepatitis virus, people who drink too much alcohol, people with a family history of liver disease, or people taking medicines that can occasionally damage the liver.
People with mild symptoms, such as tiredness, may have an ALT test to make sure they do not have chronic liver disease. ALT is often used to assess the treatment of people with liver disease and may be requested on its own or with other tests.
What does the test result mean?
Very high ALT values (more than 10 times the upper reference limit) are usually caused by acute hepatitis, often due to a viral infection. In acute hepatitis ALT values remain high for 1-2 months but can take 3 to 6 months to return to normal.
In chronic hepatitis ALT values are not as high, often less than 4 times the upper reference limit: in chronic hepatitis ALT values range from normal to moderately raised, which is why the doctor will often repeat the test to see how it changes. In some liver diseases, especially when the bile ducts are blocked, or in cirrhosis or some types of liver cancer, ALT may be very close to normal.
Is there anything else I should know?
An intramuscular injection or very intense physical exercise can raise ALT levels.
In rare cases some medicines can damage the liver or muscles, causing a rise in ALT. This can be true of both prescription medicines and some “natural” products. If high ALT values are found, it is very important to tell your doctor about all the medicines or products you are taking.
1. What is hepatitis?
2. What other tests are used to assess liver disorders?
1. What is hepatitis?
Hepatitis is inflammation of the liver. There are two broad categories: acute and chronic. Acute hepatitis causes noticeable flu-like symptoms, often with loss of appetite and sometimes diarrhoea and vomiting. In some cases of hepatitis the urine turns brown, the stools pale and the skin and eyes yellow. Most people affected recover completely. Chronic hepatitis usually causes no symptoms or only a lack of energy and tiredness; many people do not know they have it. In some people chronic hepatitis can gradually damage the liver and, after many years, lead to liver failure.
2. What other tests are used to assess liver disorders?
Other tests commonly used to assess liver disease include other enzymes found in liver cells, such as aspartate aminotransferase (AST) and alkaline phosphatase (ALP), and bilirubin (a yellow pigment present in the blood and removed by the liver).