Alanine Aminotransferase (ALT/SGPT), Serum

What it is:
Alanine aminotransferase (ALT), also known as serum glutamate pyruvate transaminase (SGPT), is an enzyme found mainly in the liver. The test measures ALT levels in the blood and is commonly used as a marker of liver health.

Uses

• Diagnose and monitor liver diseases (hepatitis, cirrhosis, fatty liver disease)

• Assess liver injury due to medications, toxins, or alcohol

• Monitor patients receiving hepatotoxic drugs

• Evaluate unexplained symptoms such as jaundice, fatigue, or abdominal pain

Symptoms That May Lead to the Test

• Jaundice (yellowing of skin/eyes)

• Dark urine, pale stools

• Fatigue and weakness

• Abdominal pain or swelling

• Nausea and loss of appetite

• History of alcohol or drug use affecting the liver

Abnormal Results

• High ALT levels:

  • Acute or chronic hepatitis (viral, alcoholic, autoimmune)

  • Fatty liver disease (NAFLD/NASH)

  • Cirrhosis

  • Liver tumors or metastasis

  • Drug or toxin-induced liver injury

  • Biliary obstruction

• Low/normal ALT levels:

  • Normal liver function or recovery

  • Not usually clinically significant on its own

Risks

• Minimal, limited to standard blood draw risks (mild pain, bruising, dizziness).