Alanine Aminotrasferase (ALT)

About this test

Alanine aminotransferase (ALT) is a liver enzyme. This test measures the level of ALT in the blood.

ALT converts the amino acid alanine into pyruvate for cellular energy production. Normal ALT levels in the blood are low. When the liver is damaged more ALT is released into the blood and can be detected often before symptoms such as jaundice are present making ALT a useful test for early detection of liver damage.

Many conditions can cause damage to liver cells giving a rise to ALT. Inflammation to the liver is called hepatitis and can be caused by viruses or medication or substances that are toxic to the liver.

ALT is often tested in conjunction with aspartate aminotransferase (AST) or as part of the groups test called Liver Function Tests (LFT).

Many conditions can cause damage to liver cells giving a rise to AST. Inflammation to the liver is called hepatitis and can be caused by viruses or medication or substances that are toxic to the liver.

AST is often tested in conjunction with alanine aminotransferase (ALT) or as part of the groups test called Liver Function Tests (LFT).

Who is this test for?

ALT tests are used to evaluate the liver in the presence of the following signs and symptoms:

• Weakness, fatigue
• Poor appetite
• Nausea, vomiting
• Abdominal pain
• Jaundice (Yellow discoloration)
• Change in urine colour to dark
• Pale stool
• Skin itching