What is the liver?
The liver is a large organ that lies on the right in the upper abdomen. It is an important organ: a healthy liver is vital for healthy living.
What does the liver do?
The liver carries out many different processes: it detoxifies the blood and synthesises proteins for growth, development, and repair. The liver also generates many of the chemicals and enzymes needed for digestion.
When liver function is impaired, this can mean the body is unable to excrete waste products or to make essential blood components, including proteins and clotting factors. Liver problems can be due to a wide range of causes, and the Gastroenterology and Hepatology team at The Physicians' Clinic have particular experience and expertise in all aspects of diagnosing and managing liver problems.
How is the function of the liver checked?
Liver function tests check for the levels of various proteins, comparing the measured level with the normal range. While there will always be some natural variation in the levels, marked deviation from the normal range of liver function tests may indicate a problem.
However, the liver is a complex organ so it should not be a surprise that liver function test results need expertise to interpret:
- Although many liver problems cause no symptoms in the early stages, abnormal liver function tests can show that something is wrong.
- Abnormal liver function tests may occur even when there is no significant liver damage.
- Problems indicated by abnormal liver function tests may lie within the liver itself or may be due to impaired drainage of waste products from the liver through the bile duct and into the gall bladder. This can occur if a gallstone lodges in the bile duct and blocks it.
Liver function tests measure a range of blood components:
- Aspartate aminotransferase (AST)
- Alanine aminotransferase (ALT)
- Alkaline phosphatase (ALP)
- Gamma glutamyltransferase (GGT).
Tests that check whether blood clotting is normal may also be performed.
If the initial liver function tests are abnormal, the Gastroenterology and Hepatology team will advise more tests to identify the type and extent of liver disease, including:
- Further blood tests, to investigate or exclude causes of liver damage, including hepatitis B or C, or autoimmune liver disease.
- Ultrasound/CT/MRI scans, to look at the appearance of the liver in detail. Scans can reveal evidence of fatty liver changes, a bile duct blockage, significant liver scarring, or liver tumours.
- Fibroscan. This is a non-invasive scan that has been developed recently. It is not widely available but is performed by the team at The Physicians' Clinic.
A Fibroscan assesses the degree of fibrosis (scarring) present in the liver. Significant fibrosis may progress to liver cirrhosis, which has important health implications.
Until recently the only way of making this assessment was with an invasive liver biopsy, as liver function tests and standard scans provide relatively poor information concerning the degree of fibrosis.
Although liver biopsies are still sometimes needed, a Fibroscan is extremely useful as it is an entirely non-invasive, painless and safe way of assessing liver damage.
The Gastroenterology and Hepatology team at The Physicians' Clinic uses Fibroscan results in conjunction with other scans and blood tests to allow us to assess the extent of liver damage and to provide an accurate diagnosis. This then allows treatment approaches to be put in place to reduce or reverse any damage caused.
What are the most common liver problems?
Liver problems can be either:
- Acute (they have started recently and come on quickly). Acute liver problems often develop with no previous history of liver problems. Liver function tests are usually abnormal and the person affected will have clinical symptoms, including jaundice (yellowing of the eyes and sometimes the skin). A new case of jaundice always needs urgent assessment.
- Chronic (they have come on slowly and persist).
There is a lot of overlap between the causes of acute and chronic liver disease, which include:
- Viral hepatitis. Hepatitis A, B, C, and E may all cause acute hepatitis, and hepatitis B and C can persist, causing chronic liver disease.
- Alcohol may cause a range of acute and chronic liver problems, including fatty liver, hepatitis, and cirrhosis.
- Non-alcoholic fatty liver disease (NAFLD). This is a common cause of chronically abnormal liver function tests and is often associated with a range of other conditions, including diabetes, obesity, and high blood pressure.
- Autoimmune liver diseases. These include autoimmune hepatitis, primary sclerosing cholangitis (PSC), and primary biliary cirrhosis (PBC). It remains uncertain what causes these conditions, but they can all cause chronic liver problems.
- Drug-induced liver disease. A wide range of prescribed and non-prescribed medications can cause either acute liver injury/failure (eg paracetamol overdose), or more chronic problems leading to persistently abnormal liver function tests.
- Haemochromatosis. Excess iron in the body can damage the liver and other organs. This genetic condition is straightforward and important to diagnose, and treatment is highly effective.
- Gallstones. Most people who have gallstones have not symptoms as the stone remains in the gall bladder. In others, they can cause a range of problems. Blockage of the bile duct by stones can cause pain and jaundice. Prompt and detailed investigation is essential in order to exclude rarer causes of bile duct obstruction. These include benign or cancerous tumours or strictures (narrowing of the bile duct). In all cases, urgent treatment follows.