Patient education: Aminotransferase tests (The Basics)

What is an aminotransferase test? — This is a blood test that checks how well the liver is working. It measures 2 substances in the blood:

●Alanine aminotransferase, or "ALT"

●Aspartate aminotransferase, or "AST"

Both ALT and AST are "enzymes" that are made in the liver. Enzymes help keep the body working normally. If the liver is injured or damaged, it might release more enzymes than usual.

Why might I need an aminotransferase test? — Your doctor might order these tests:

●If you have symptoms of a liver problem

●If you are at risk for developing liver problems

●As part of a routine check-up

●To check how well your liver is working, if you have already been diagnosed with a liver problem

●To monitor side effects from certain medicines

How do I prepare for an aminotransferase test? — For this test, you need to get a "blood draw." Your doctor or nurse will tell you where to go for this.

It might help to wear a short-sleeve shirt to your blood draw appointment. This makes it easier for the person drawing your blood to get to your arm.

What happens during a blood draw? — For the blood draw, a needle is used to take a small amount of blood from your arm (figure 1). Collecting the blood only takes a few minutes. The blood is then tested in a lab.

Tell the person who takes your blood:

●If you take "blood thinner" medicines or if you have a bleeding problem – They will make sure that your bleeding is under control before you leave.

●If you have a latex allergy – Some of the supplies used for blood draws might contain latex.

●If you have a preferred arm to use

Most of the time, getting blood taken does not cause problems. You might have a little soreness or bruising where the needle went in. Rarely, people get lightheaded.

What do my results mean? — Your doctor or nurse will tell you when to expect your results, and will contact you with the results. Or if you use an online "patient portal," you might get an alert there when your results are ready.

If your test shows that your ALT or AST is high, your doctor or nurse will talk to you about what to do next. They might need to do more tests to figure out what the cause is.

If you do have a health problem, your doctor will work with you to come up with a plan for treatment.

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Patient education: Cirrhosis (Beyond the Basics)
Patient education: Metabolic dysfunction-associated steatotic liver disease (Beyond the Basics)
Patient education: Alcohol use — when is drinking a problem? (Beyond the Basics)
Patient education: Hepatitis B (Beyond the Basics)
Patient education: Hepatitis C (Beyond the Basics)
Patient education: Esophageal varices (Beyond the Basics)