In short
- ALT (alanine aminotransferase) is an enzyme found mainly in the liver and is an important marker of liver health.
- When liver cells are damaged, the ALT level in the blood can increase.
- An elevated ALT level usually does not cause symptoms directly and is often discovered during a blood test.
- Abnormal levels can have various causes, such as fatty liver disease, alcohol consumption, medication, a viral infection or other liver conditions.
- A liver function blood test can provide insight into possible liver damage or stress.
- An elevated ALT level does not automatically mean that you have a serious liver disease; further testing may be necessary.
- ALT is often assessed together with other liver markers, such as AST, gamma-GT and bilirubin, to provide a more complete picture of liver function.
- Would you like to know more about your liver health? A liver function blood test can provide early indications of a possible liver condition.
What is ALT and what does this level say about your liver?
ALT stands for Alanine Aminotransferase. It is an enzyme, a type of protein, that is found mainly in the liver. The amount of ALT in your blood provides information about the health of your liver. When liver cells are damaged, more ALT is released into the blood. A normal ALT level usually indicates a healthy liver.
What does a high or low ALT level mean?
A high ALT level usually means that there may be a problem with your liver. This can be caused, for example, by inflammation or damage to the liver. A low ALT level is uncommon and is usually not a cause for concern. It generally provides little information about your health.
What symptoms can indicate an abnormal ALT level?
With an abnormal ALT level, you may experience symptoms such as fatigue, nausea, jaundice (yellowing of the skin or eyes), dark urine or pain in the upper right side of the abdomen. Sometimes there are no symptoms at all, and an abnormal level is discovered by chance during a blood test.
What can cause ALT levels to increase or decrease?
ALT levels can be elevated due to liver diseases such as hepatitis (inflammation of the liver), excessive alcohol consumption, certain medications, fat accumulation in the liver (fatty liver disease), or a viral infection. Intense exercise can also temporarily increase ALT levels. A low ALT level usually has no medical significance.
What conditions can cause an abnormal ALT level?
Conditions that can cause an elevated ALT level include hepatitis, liver cirrhosis (severe liver damage), fatty liver disease, bile duct problems, certain inherited conditions and, in some cases, heart or muscle disorders. Certain medications and excessive alcohol consumption can also increase ALT levels.
When should you consider having your ALT tested?
It may be advisable to have your ALT tested if you have symptoms that could indicate liver problems, such as fatigue, jaundice or abdominal pain. If you are at increased risk of liver disease, for example due to being overweight, diabetes, excessive alcohol consumption or the use of certain medications, it may also be useful to have your ALT level checked.
How is ALT measured and how should you interpret the result?
ALT is measured using a finger-prick blood test, after which the laboratory determines the amount of ALT in your blood. The result is compared with the normal reference values, which may vary between laboratories. If the level is higher than normal, this may indicate a liver problem. Your doctor will consider the result together with any symptoms to determine what it may mean in your situation.
How can an abnormal ALT level be improved?
To improve an abnormal (elevated) ALT level, it is important to keep your liver as healthy as possible. This can include eating a healthy diet, limiting alcohol consumption, maintaining a healthy weight and using medications carefully. In some cases, treatment of an underlying condition may be necessary. Always discuss with your doctor what is most appropriate for you.
