Alanine aminotransferase (ALT) is an enzyme primarily found in the liver, but also present in kidneys, heart, and muscles. The ALT test is conducted to detect potential damage or diseases in the liver. Conditions that harm liver cells can cause elevated ALT levels, impacting various bodily functions. Therefore, the ALT test is a crucial indicator for evaluating liver health and diagnosing liver diseases.

Specifically, the ALT test is used in the diagnosis of the following conditions:
* Fatty liver disease
* Hepatitis
* Cirrhosis
* Liver cancer

Furthermore, the ALT test can be utilized in the diagnosis and monitoring of conditions such as obesity, diabetes, and heart failure.