What Is a Blood Test?

By taking and testing a small sample of a person’s blood, doctors can check for many kinds of diseases and conditions. Blood tests help doctors check how the body’s organs are working and see if medical treatments are helpful.

To help your child get ready for a blood test, find out if they need to fast (not eat or drink) or should stop taking medicines before the test. Explain what to expect during the test. If your child is anxious about it, work together on ways to stay calm.

What Is ALT?

Alanine aminotransferase (AL-uh-neen uh-mee-no-TRANS-fur-ace), or ALT, is an enzyme that helps the liver convert food into energy. High enzyme levels can be a sign that the liver is injured or irritated, and the enzymes are leaking out of the liver cells.

Because ALT used to be called serum glutamic-pyruvic transaminase, or SGPT, this is sometimes called an SGPT test.

Why Are ALT Tests Done?

This test measures the level of ALT in the bloodstream. Doctors might order it if a child has signs of a possible liver problem, such as jaundice (yellowish skin or eyes), dark pee, nausea, vomiting, or belly pain. It also might be done if a child is on medicine that makes high liver enzyme levels more likely.

What if I Have Questions?

If you have questions about the ALT test, or what the test results mean, speak with your doctor.