High ALT level in a blood test

ALT is an enzyme found mainly inside liver cells. It can enter the bloodstream when those cells are stressed or damaged. A raised result may follow infection, alcohol exposure, fatty change in the liver, some medicines or supplements, strenuous exercise, or another liver-related problem. Sometimes a temporary rise settles on repeat testing.

Your clinician will compare ALT with other liver tests and your symptoms. The pattern, degree and persistence of changes matter more than one isolated value. A result is not the same as a diagnosis of liver disease.

Book a review, bring the report and list every prescription, over-the-counter product and supplement you use. Avoid alcohol until you have received personalised advice, and do not stop essential medicine unless the prescriber tells you to. You may be offered repeat blood tests or additional assessment based on the pattern.

Tell the clinician about recent illness, intense exercise, abdominal symptoms and possible exposure to infection. Conditions such as [Glandular Fever](/conditions/glandular-fever/) can be relevant to the history.

Contact a clinician promptly if you develop yellow skin or eyes, very dark urine, pale stools, worsening pain under the ribs, repeated vomiting, unusual drowsiness or confusion. Seek emergency help for severe confusion, collapse or rapidly worsening illness.

Ask what the ALT result is alongside the laboratory range, whether other liver tests changed, whether a repeat test is needed, and whether any medicine, supplement, alcohol use or recent illness could explain it. Also ask which symptoms should trigger urgent contact.