What Do Elevated Liver Enzymes Really Mean?
If you’ve had a complete metabolic profile, Chem 14 performed, or a Liver Function Test (LFT) your liver enzymes have likely been tested. What exactly are liver enzymes, why are they important, what does it mean if they are abnormal, and is there further testing that should be performed?
What are the liver enzymes?
The most commonly tested enzymes that signal liver problems are ALT, AST, and ALP and they are usually part of a Chem 14. ALT stands for Alanine Transaminase, but it is also called Alanine Aminotransferase as well as SGPT. The enzyme ALT is produced primarily in the liver. Other organs and tissues such as the kidneys, heart, and muscle have a much lower level of ALT. As the liver contains the highest amount of ALT it is a very helpful test to check on the health of the liver.
AST stands for Aspartate Transaminase, but it is also called Aspartate Aminotransferase as well as SGOT. The enzyme AST is produced in the liver and other organs in the body such as the heart, kidneys, and muscles. ALK stands for alkaline phosphatase and is sometimes abbreviated ALKP. The enzyme ALK is found in many tissues in the body with the highest amounts in the bones, intestines, brain, and liver.
Why are the tests ordered?
The liver performs many functions in the body, such as removing toxins, making proteins, breaking down red blood cells, and making digestive enzymes to name a few.
The purpose of testing one or more of these enzymes is to determine if you have normal levels of the enzymes. When tissues and organs are damaged or diseased, they can leak enzymes into the bloodstream.
A damaged liver can leak any or all of the liver enzymes, ALT, AST, and ALK, increasing the measured levels. As an increase may occur before symptoms appear, it is important to screen any possible liver problems early.
How should you prepare for the test?
A blood sample is required. Certain foods and medications can affect your liver enzyme levels. Check with your doctor about what medications can affect your results. While testing for ALT, AST, and ALK normally does not require fasting, if other tests are ordered you may be requested to fast. Since AST can be elevated from muscle damage, do not perform rigorous exercise prior to this test.
What do the results mean?
There are many reasons for elevated liver enzymes are viruses, bile duct blockages, inherited diseases, alcohol, medications, cancer, infection, or your own immune system could even be attacking your liver. Certain conditions can cause certain liver enzymes to be elevated while the other liver enzymes are not elevated. Here are some common patterns to help you understand your liver enzyme results:
Alcohol: AST is usually twice as high as ALT.
Cirrhosis: This is a term for scarring of the liver. Causes of cirrhosis include drugs, alcohol, fatty liver disease, and chemotherapy. Cirrhosis usually causes mild elevations in ALT and AST.
Viral Hepatitis: Sudden or acute virus infections cause very elevated AST and ALT results. Viral hepatitis B, C, and D cause moderate elevations, but A and E can cause high elevations. Other viruses include HIV, cytomegalovirus (CMV), and Epstein-Barr virus (EBV).
Autoimmune Hepatitis: This is a chronic disease where the body’s own immune system attacks the liver and causes inflammation. All the liver enzymes are usually elevated, and this can cause scarring or cirrhosis.
Fatty Liver Disease: This is a condition where fat gets deposited in the liver and the liver doesn’t function properly. AST and ALT are elevated together.
Cholestasis: This is a stalling of bile flow from your liver to your digestive system. If bile doesn’t freely flow, your liver can become inflamed, causing an elevation in AST, ALT, and ALK.
Biliary Obstruction: A high ALK, AST, and ALT usually mean there’s a blockage in the duct that lets bile out of the liver, causing liver inflammation.
Questions to ask your provider
Based on my results, should I receive any follow-up testing such as viral hepatitis, platelet count, coagulation testing, GGT, or bilirubin?
Are my results being affected from my diet, medications, or any existing chronic conditions such as thyroid disease, diabetes, high lipids, or alcohol abuse?
How can I lower my liver enzyme levels?
Final takeaway
The liver is a vital and remarkably resilient organ, capable of healing when damage is identified early and addressed appropriately. Elevated liver enzymes are not a diagnosis themselves, but a critical clue that something may be affecting your liver’s function.
By understanding what these enzymes indicate and engaging in a thoughtful conversation with your healthcare provider, you can take proactive steps toward identifying the underlying cause. Whether the issue is temporary, lifestyle-related, or requires medical intervention, timely testing and follow-up can prevent more serious complications and support long-term liver health.
Don’t ignore the numbers, use them as a guide toward better health and informed decisions
Author:
Dr. Elizabeth Fisher DCLS, MHA, CC(NRCC), MLS(ASCP)CM, PBTCM is a qualified High Complexity Laboratory Director (HCLD), Clinical Consultant, and Medical Laboratory Scientist (MLS) generalist.
Sources:
Lala, V., Zubair, M., Liver Function Tests. StatPearls. Updated July 30, 2023. Accessed from: Liver Function Tests Article
American Liver Foundation. Diagnosing Liver Disease — Liver Biopsy and Liver Function Tests. Updated January 12, 2025. Accessed from: Diagnosing Liver Disease: Biopsy, Risks & Preparation
This information is not a substitute for, nor does it replace professional medical advice, diagnosis, or treatment. If you have any concerns or questions about your health, you should always consult with a healthcare professional.