What is an ALT blood test?
ALT, which stands for alanine transaminase, is an enzyme found mostly in the liver. When liver cells are damaged, they release ALT into the bloodstream. An ALT test measures the amount of ALT in the blood. High levels of ALT in the blood can indicate a liver problem, even before you have signs of liver disease, such as jaundice, a condition that causes your skin and eyes to turn yellow. An ALT blood test may be helpful in early detection of liver disease.
Other names: Alanine Transaminase (ALT), SGPT, Serum Glutamic-Pyruvic Transaminase, GPT
What is it used for?
An ALT blood test is a type of liver function test. Liver function tests may be part of a regular checkup. The test can also help diagnose liver problems.
Why do I need an ALT blood test?
Your health care provider may have ordered liver function tests, including an ALT blood test, as part of a routine exam or if you have symptoms of liver damage. These may include:
- Nausea and vomiting
- Jaundice
- Abdominal pain
- Loss of appetite
- Unusual itching
- Tiredness
Because ALT in the bloodstream can indicate liver damage before symptoms appear, your health care provider may order an ALT blood test if you are at a higher risk for liver damage. Risk factors for liver disease include:
- Family history of liver disease
- Heavy drinking
- Exposure or possible exposure to hepatitis virus
- Obesity
- Diabetes
- Taking certain medicines that can cause liver damage