Alanine transferase (ALT) is an enzyme which is mostly found in the liver, but is also found in smaller amounts in the heart, muscles and the kidneys. If the liver is damaged, ALT is leaked into to bloodstream. As ALT is predominantly found in the liver, it is usually an accurate marker for liver inflammation and can indicate liver damage caused by alcohol, fatty liver, drugs or viruses (hepatitis).
What might a low result mean?
Having low levels of ALT in your blood is completely normal.
What might a high result mean?
Raised levels may indicate that your muscles are damaged for example after intensive exercise. However, this more commonly suggests that the liver is inflamed or damaged with diseases such as hepatitis, cirrhosis or fatty liver disease.
How might I improve my result?
An elevated ALT result (in combination with other raised liver enzymes) may signify fatty liver disease or fibrosis (where inflammation has progressed to cause stiffness and scarring of the liver). Fatty liver can be caused by drinking too much alcohol, or by fat accumulating in the liver, mainly due to being overweight or obese. It is associated with diabetes, raised blood pressure and high cholesterol. There is a lot you can do to keep your liver healthy: keep your alcohol consumption to the recommended 14 units a week or less and try to have a few alcohol-free days every week; losing weight, if you need to, is important, as is eating a healthy diet, high in whole grains and fibre and plenty of fruit and vegetables, and low in processed foods, sugar and unhealthy fats.
A raised ALT caused by any drugs or medication that you are taking is normally temporary and should go back to normal once you cease your medication.