A to Z of medical tests
support our work today

When and why

The liver serves three functions: it stores and filters blood, removing toxic substances from drugs, food or body waste; it makes bile, a liquid which is stored in the gall bladder and released into the gut to help digest fat; and it metabolizes nutrients from food, releasing energy into the bloodstream and storing vitamins and minerals.

The liver can stop functioning properly for several reasons. Drugs can cause damage to liver cells, releasing enzymes into the circulation which can be measured. The liver can be damaged by alcohol, which causes a condition caused cirrhosis. Infections of the liver are called hepatitis and can result in permanent damage. Megadoses of vitamin A can also cause liver damage.

If the liver isn't working properly, the body's ability to produce protein is reduced, causing loss of muscle. Energy levels may fall and the blood may not be properly cleaned.

Liver function is commonly monitored among people taking antiretroviral therapy due to the risk of liver dysfunction. In particular, people commencing treatment with nevirapine or efavirenz will have liver function tests very regularly during the first two months of treatment.

How it will help

Blood tests can measure levels of enzymes found in the liver cells called SGOT and SGPT. These are also called AST (aspartate aminotransferase) and ALT (alanine aminotransferase). When the liver cells are damaged, these enzymes flow into the blood at increased levels. Physical symptoms of liver stress are hepatomegaly (enlarged liver) or jaundice (yellowing of the skin and eyes, because the liver is failing to break down bilirubin). Raised levels of alkaline phosphatase are indicative of obstruction or infections such as TB or MAI.

A liver biopsy is a procedure which involves taking a small piece of liver tissue to establish the extent of liver damage. A person with an active viral hepatitis infection, such as hepatitis B or C, may undergo a biopsy to determine whether or not treatment may be required.

If a drug is causing liver problems, the dose may be reduced or stopped. Ensure that you are getting a good amount of protein in your diet, and ideally avoid alcohol, caffeine and nicotine to allow your liver to recover.

There is a long history of herbal treatments for liver problems. Chickory, dandelion, wahoo, centaury, mandrake and celandine are said to promote the flow of bile and relieve jaundice. However, some alternative therapies may cause liver damage including comfrey and some Chinese herbs.