Abnormal Liver Function Tests
What does theliver do?
The liver is an important organ that sits just below the diaphragm on the right-hand side of the abdomen. Its measures approximately 15cm in width and weighs up to 1.5kg. It has multiple important functions including:
– Detoxifying the blood
– Metabolizing medications
– Breaking down red blood cells
– Producing bile and bile acids which help with digestion
– Producing important proteins
– Regulating glycogen (carbohydrate) and fat metabolism
What are liver function tests?
Liver function tests, or LFTs, refer to a set of routine blood tests that measure some of the important processes involved in the functioning of the liver. These include:
Taken together, the LFTs form a pattern that can give important clues as to the health of the liver and possible reasons for poor function. The broad patterns of disease include:
(i) Hepatitic picture (high AST/ALT)
This is seen when there is a problem directly affecting the liver cells such as an infection, drug toxicity, autoimmune condition or impaired blood flow.
(ii) Obstructive picture (high GGT, ALP, Bilirubin)
This picture is typically seen when there is a problem affecting the drainage of the liver. This can be caused by conditions such as gallstones or a tumour blocking the bile ducts. A severe blockage can lead to build up of bilirubin causing a yellowish tinge to the skin and eyes (jaundice).
(iii) Mixed picture (all can be elevated)
Seen in multiple conditions with a broad range of potential diagnoses.
Do abnormal liver function tests cause symptoms?
Most patients with mildly abnormal LFTs do not have any symptoms. However, as the liver function get worse, some patients start to feel generally unwell. This often manifests as fatigue, poor appetite, nausea and occasionally abdominal pain. Blockage to the bile outflow of the liver commonly causes itch, dark urine, pale stools and jaundice.
How do you diagnose Abnormal Liver Diseases?
Diagnosing the cause of abnormal LFTs and the underlying liver problem, requires a thorough history and examination. Additional blood tests are often required to determine the potential cause of the problem.
An ultrasound of the liver is a particularly useful test to check the appearance of the liver, the liver blood vessels, as well as the gallbladder and bile ducts.
A Fibroscan is a special type of liver ultrasound that measures the ‘stiffness’ of the liver. This correlates well with the amount of scar tissue present and gives a good idea into whether cirrhosis (scarring) is present.
If the above tests have not revealed a diagnosis, then a liver biopsy is occasionally required.
How do you treat Abnormal Liver function tests?
The treatment depends on the many underlying liver conditions to prevent scarring and long-term liver failure.