Chemical Pathology


The most common cause of a raised ALT (up to 3-4x upper limit of normal) is fat deposits in the liver. This may develop into clinically significant pathology. The raised ALT may also indicate other disease states which may be investigated using the tests below.

1. Exclude possible drug causes including:

  • Statins
  • Non-steroidal anti-inflammatory drugs
  • Herbal remedies

2. If no drug involvment, or after withdrawal of suspect drug, repeat the ALT and other LFT's in 2-3 months (sooner if ALT >150 U/L). Advise abstinence from alcohol and weight loss if appropriate during this period.

3. If ALT remains abnormal then arrange further investigations:

Further tests

  • Ultrasound scan

Bloods for:-

  • hepatitis B & C serology
  • Lipids
  • Ferritin and transferrin saturation
  • Auto-immune profile
  • Immunoglobulins
  • Coeliac serology (TTG)
  • Alpha-1-antitrypsin
  • Caeruloplasmin (if the patient is under 40 y of age and no acute illness (&/or 24h urine copper)

4. If these results are normal and ALT remains greater than 100 U/L then a referral to the GI medicine team is advised to discuss the merits of a liver biopsy in the context of the diagnostic uncertainty surrounding fatty liver.

Further guidelines for investigation and management of liver abnormalities are available to Acute Unit Staff on the Intranet.