ALT Blood Test

ALT Blood Test

What is an ALT Blood Test?

ALT stands for alanine transaminase. It is an enzyme found mostly in the liver. An ALT test measures the amount of ALT in the blood.

When liver cells are damaged, they release ALT into the bloodstream. High levels of ALT in your blood may be a sign of a liver injury or disease. Some types of liver disease cause high ALT levels before you have symptoms of the disease. So, an ALT blood test may help diagnose certain liver diseases early.

Other names: Alanine aminotransferase (ALT), Serum Glutamic-Pyruvic Transaminase (SGPT), GPT
What is it used for?

An ALT blood test is often part of a routine blood screening to check the health of your liver. The test may also help diagnose or monitor liver problems.
Why do I need an ALT blood test?

Your health care provider may order an ALT blood test, as part of a routine checkup. An ALT test is usually done with a group of other liver function tests that check how well your liver is working. These tests may also be ordered if you have symptoms of liver damage, such as:

    Nausea and vomiting
    Lack of appetite
    Fatigue
    Weakness
    Jaundice, a condition that causes your skin and eyes to turn yellow
    Swelling and/or pain in your abdomen (belly)
    Swelling in your ankles and legs
    Dark-colored urine (pee) and/or light-colored stool (poop)
    Frequent itching

Your provider may also order an ALT blood test if you have a high risk for liver damage because of:

    A family history of liver disease
    Alcohol abuse disorder (AUD)
    Obesity
    Diabetes
    Taking certain medicines that can cause liver damage
    Hepatitis or exposure to hepatitis