What is an ALT measurement?

An ALT measurement is a blood test that detects the amount of the enzyme alanine aminotransferase (ALT) in your blood. ALT is found mostly in liver cells. High levels of ALT in the blood may indicate liver damage. When liver cells are injured, they release this enzyme into the blood. A high ALT measurement may also be an indication of a liver disease, such as cirrhosis or hepatitis.

Your doctor may order an ALT measurement test if you are experiencing certain symptoms associated with liver disease including:
  • extreme fatigue
  • jaundice (yellowing of the skin and whites of the eyes)
  • loss of appetite
  • abdominal swelling or pain
  • dark urine
  • light colored bowel movements
  • itching

Continue Learning about Lab Tests

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.