Platform
Company
Immunology & Autoimmune
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Currently under review
Pending specialist review and validation.
Alanine aminotransferase is an enzyme made mostly by liver cells. It helps your body use amino acids, the building blocks of proteins. When liver cells are irritated or injured, this enzyme can move from the liver into the bloodstream, where it can be measured with a blood test.
ALT is commonly included in a liver panel along with other tests. While the liver is the main source, smaller amounts can be found in other tissues. Your clinician uses ALT to get a snapshot of how your liver is doing at the time of the test.
ALT helps detect liver irritation or injury from causes such as viral infections, fatty liver, alcohol use, autoimmune disease, or blockages in bile flow. It is often ordered when you have symptoms that could point to liver problems, like tiredness, nausea, light colored stools, dark urine, yellowing of the skin or eyes, or right upper belly discomfort.
ALT is also used to monitor known liver conditions and to watch for possible effects of certain medicines or supplements on the liver. Understanding your ALT result in context can guide next steps, such as lifestyle changes, medicine adjustments, or further testing when needed.
Your ALT result is interpreted together with your history, symptoms, exam, and other blood tests. A small, temporary rise can happen with common issues such as a short illness, recent strenuous activity, or a new medicine. Your clinician may repeat the test to see if it returns to your usual pattern.
If ALT remains higher than expected or rises along with other liver markers, your clinician may look for causes such as viral hepatitis, fatty liver related to weight or metabolic health, alcohol use, medication or supplement effects, autoimmune liver disease, or inherited conditions. If ALT is lower than expected, it is usually not concerning and can reflect body composition or nutrition. Ask your clinician how your results fit your overall health and whether any follow up is advised.
Reference intervals vary by laboratory, analyzer, methodology, population, and units. The ranges shown here are for education only. Always interpret your results against the reference interval printed on your own lab report.
Acetaminophen, statins, isoniazid, valproate, certain antibiotics, and some herbal or bodybuilding products can raise ALT. Always list all prescriptions, over the counter drugs, and supplements you take.
Recent or ongoing alcohol use can irritate the liver and increase ALT. Reducing or avoiding alcohol often helps ALT return toward your usual pattern.
Extra body weight, insulin resistance, and fatty liver can raise ALT. Gradual weight loss, balanced nutrition, and regular activity can improve liver enzyme patterns over time.
A recent viral illness or very strenuous exercise can cause a temporary ALT rise. Results often improve after recovery and rest.
Hemolysis, delayed processing, or storage issues can affect enzyme results. Fasting is usually not required, but consistent timing and proper collection improve reliability.
Pregnancy, older age, and lower muscle mass can influence ALT. Children may have different typical patterns. Your clinician will interpret results with these factors in mind.
References