During your annual physical, your primary care team ran typical, routine labs. Scrolling through your online patient portal to view the results, you’re shocked to see some labs flagged as red — your liver enzymes are elevated. Then your health care team sends you a message recommending that you see a liver specialist. What exactly is going on?
One of the most common reasons for a referral to a liver specialist, known as a hepatologist, is elevated liver enzymes found during routine tests. When this happens, it’s natural to have questions.
What is a liver enzyme?
There are three main lab values that are commonly evaluated in relation to liver health: aspartate aminotransferase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP). AST and ALT are markers of liver cell injury. ALP is linked to injury of the bile ducts — a series of tubes that carry the bile produced by the liver cells and empty into the intestines.
Although considered liver injury tests, elevation in any or all of these enzymes does not necessarily mean you have liver damage. These enzymes are produced by other organs as well. For example, AST increases with muscle damage such as in a heart attack or muscle trauma. ALP is also produced by bone and in the placenta during pregnancy. ALT is the most specific enzyme to the liver itself.
Typical ranges can vary between the sexes, based on age and at different laboratories. Generally speaking, the upper limit of typical for AST and ALT for men is 35 to 40 units per liter (U/L) and for women is 25 to 30 U/L. The upper limit of typical for ALP is around 115 U/L for men and 100 U/L for women.
What does it mean if my liver enzymes are elevated?
Mild to moderate elevation in liver enzymes often means there is some type of inflammation within the liver. This matters because if the inflammation continues unabated for long enough, you could develop scarring in the liver, known as fibrosis. Stages of fibrosis range from 0 to 4:
- Stage 0 means there is no scarring.
- Stage 1 means there is mild scarring.
- Stage 2 means there is moderate scarring.
- Stage 3 means there is advanced scarring.
- Stage 4 is advanced liver disease, known as cirrhosis.
It’s best to evaluate liver enzymes early to hopefully prevent any progression of scarring, especially to cirrhosis. Generally, if you have not reached stage 4, fibrosis is reversible.
What causes liver enzyme elevation?
The most common response we hear after someone is told they have elevated liver enzymes is, “Wait, doctor, I don’t drink heavily. How could I have liver damage?”
This confusion is understandable because alcohol use disorder is a major cause of liver damage. But there are many other causes of elevated liver enzymes, including:
- Viral hepatitis, such as hepatitis B, C and D.
- Autoimmune disease caused by malfunctions of the immune system, such as autoimmune hepatitis, primary biliary cholangitis and primary sclerosing cholangitis.
- Nonalcoholic fatty liver disease. This means there is too much fat stored in the liver cells and can be linked to obesity and diabetes. As the name implies, this disease can be independent of alcohol use.
- Genetic causes such as the inherited condition alpha-1 antitrypsin deficiency or hemochromatosis.
By far, the most common causes are alcohol use disorder and nonalcoholic fatty liver disease. There has been a worldwide increase in obesity and its complications, such as diabetes. Alcohol use also has increased during the COVID-19 pandemic, which has added to the prevalence of liver problems over the last decade.
However, it’s also possible that your elevated liver enzymes could be the result of a medication you’re taking. Both prescription and nonprescription medications can cause abnormalities in the liver enzymes.
For this reason, it’s very important to be careful with any nonprescription medications or supplements. Remember that even if supplement ingredients are found in nature, unintended effects and interactions with other medicines are possible. In general, it’s best to check with your health care team prior to starting a new supplement or medication.
Is my liver failing?
Short answer: No!
In the vast majority of people with mild to moderate liver enzyme elevation who don’t have other symptoms, the liver is not failing.
Liver failure is a distinct medical condition, and it’s divided into two different categories: acute, meaning a rapid onset, and chronic, which means liver failure has been ongoing for years. Both can come with signs and symptoms such as confusion, an inability to form blood clots appropriately, and yellowing of your eyes and skin known as jaundice.
What happens next after an elevated liver enzyme result?
Typically, the initial step is an evaluation beginning with a thorough history and physical exam looking for any signs or symptoms that could relate to chronic liver disease.
Additionally, a number of nonliver causes of liver enzyme elevations should be considered. Most commonly, these include abnormalities of the thyroid or gastrointestinal tract, such as celiac disease or gallstones.
Your health care team will typically order a series of laboratory tests to look for specific causes of elevated liver enzymes and may request an abdominal ultrasound to look for any structural abnormalities of the liver.
If the labs or imaging confirm a diagnosis of underlying liver disease, your health care team will create a specific management plan for you. However, in a small percentage of people, diagnosis will remain elusive despite persistent elevation in liver enzymes. In this group, a liver biopsy may be needed to gather more information.
The bottom line
A test result with elevated liver enzymes is not rare. Your liver is not necessarily failing.
But it is important that you review these results with your health care team or see a hepatologist to ensure there is no advanced scarring present and to identify the underlying cause.
The bottom line: Fibrosis can be reversible!
