The Alanine Amino Transferase (ALT) test, also known as Serum Glutamic Pyruvic Transaminase (SGPT), is a blood test that measures the levels of the ALT enzyme in the blood. ALT is an enzyme found primarily in the liver, but also in smaller amounts in the kidneys, heart, and muscles. The ALT test is commonly used to evaluate liver function and diagnose liver diseases such as hepatitis or cirrhosis. Elevated levels of ALT in the blood can indicate liver damage or disease, while low levels are typically not of concern. The ALT test involves taking a small sample of blood, which is then analyzed in a laboratory to determine the levels of the enzyme. Depending on the results of the test, doctors may recommend additional diagnostic tests or treatments to address underlying conditions. Regular monitoring of ALT levels can also be used to track the progression of liver disease and evaluate the effectiveness of treatment.