If you place your right hand over the area under the ribs on the right side of your body it will just about cover the area of your liver. The liver is the largest gland, and the largest solid organ in the body, weighing some 1.8 kgs in men and 1.3 kgs in women. It holds approximately 13% (about one pint or 0.57 litres) of your total blood supply at any given moment and is estimated to have over 500 functions.

The liver is dark reddish brown in colour and is divided into two main lobes (the much larger right and the smaller left) which are further subdivided into approximately 100,000 small lobes, or lobules. About 60% of the liver is made up of liver cells called hepatocytes which absorb nutrients and detoxify and remove harmful substances from the blood. A hepatocyte has an average lifespan of 150 days. There are approximately 202,000 in every milligram of your liver tissue. Two-thirds of the body of your liver is the parenchyma, which contains the hepatocytes, and the remainder is the biliary tract. It receives its blood supply via the hepatic artery and portal vein (which transports nutrients from your intestine, or gut).


The principal roles of the liver include removing toxins from the body, processing food nutrients and helping to regulate body metabolism. A range of conditions can prevent the liver from performing its vital functions. Culprits include fat accumulation, alcohol misuse, viral infection, iron or copper accumulation, toxic damage and cancer.

The most common cause of liver disease is non-alcoholic fatty liver disease (‘fatty liver’). Cirrhosis is the end-result of many liver conditions and involves severe scarring of the liver (with liver nodule formation). It is associated with a progressive decline in liver function resulting in liver failure.

Functions of the liver
Some of the many functions of the liver include:

• Drugs, including alcohol, are filtered through the liver and neutralised or converted into other forms by special enzymes.
• Bile, produced by the liver, is stored in the gall bladder and used to help break down dietary fats.
• Fat soluble vitamins A, D, E and K need bile in order to be absorbed by the body.
• The liver converts carbohydrates into glucose for instantly available energy and converts glucose into its storable form (glycogen). When blood sugar levels drop, glycogen is converted back into glucose.
• Amino acids from protein are sent to the liver for the production of body proteins such as hormones.
• The liver changes ammonia (a toxic by-product of protein metabolism) into urea, which is then excreted in urine.

Symptoms of disease
Symptoms of liver disease depend on the disorder, but can include:

• Jaundice (the skin or whites of the eye turn yellow)
• Dark urine
• Nausea
• Vomiting
• Diarrhoea
• Appetite loss
• Weight loss
• General malaise
• Fever
• Bloated abdomen, swollen ankles
• Abdominal pain in the upper right side
• Anaemia, vomiting blood or passing black stools (denoting altered blood)
• Changes in mental state – altered sleep pattern (awake at night), confusion, drowsiness.
  

A range of causes
Some of the causes of liver disease include:

• Non-alcoholic fatty liver disease (‘fatty liver’)
• Hepatitis virus infections
• Alcohol-related liver disease
• Toxic effect of medications, herbal medicines
• Congenital or inherited abnormalities of the liver – involving accumulation of iron and copper in the body and some rare enzyme disorders
• Conditions leading to liver cell and/or bile duct (the plumbing system’ of the liver) damage.
   

A range of disorders

Some disorders of the liver include:

• Fatty liver – this is the most common of the alcohol-induced liver disorders. Fat accumulates inside the liver cells, causing cell enlargement (steatosis) and sometimes cell damage (steatohepatitis), and can lead to cirrhosis. Similar changes are also seen in people who do not drink excessive amounts of alcohol but are overweight, obese or have diabetes. The liver becomes enlarged, causing discomfort on the upper right side of the abdomen.
• Cirrhosis – this has many causes but is commonly due to hepatitis infection or excessive alcohol intake. The cells of the liver are progressively replaced by scar tissue, which seriously impairs liver functioning.
• Hepatitis – a general term meaning inflammation of the liver. It is also used to refer to infections of the liver by specific viruses (hepatitis A to E).
• Haemochromatosis – this inherited disease makes the body absorb and store higher than normal amounts of iron. This damages many organs including the liver, pancreas and heart.
• Autoimmune liver disorders – an abnormal increase in immune cells damages the liver cells. These rare conditions include autoimmune hepatitis and primary biliary cirrhosis (mostly women affected) and primary sclerosing cholangitis (more common in men).
• Cancer – primary cancers can arise in the liver, most often from chronic hepatitis with cirrhosis. Stray cancer cells from a tumour elsewhere in the body may cause a secondary tumour in the liver.
• Galactosaemia – the body’s reaction to particular milk sugars damages the liver and other organs. This is a rare inherited disorder.
• Alpha 1-antitrypsin deficiency – another rare inherited disorder that can cause cirrhosis of the liver.
• Wilson’s disease – the liver can’t excrete copper. Various organs of the body, including the liver and brain, are affected by the excessively high copper levels.
  

Complications of liver disease
Without treatment, a person with liver disease is susceptible to a wide range of complications, including:

• Hepatic encephalopathy – scar tissue prevents the proper flow of blood through the liver, so that toxins remain. These circulating toxins, particularly ammonia, affect brain functioning and can lead to a coma.
• Ascites – liver disease can cause a build-up of body sodium (‘salt’), which leads to fluid retention in the abdominal cavity (ascites) and in the legs, feet and back (oedema).
• Liver failure – the liver cells are destroyed faster than the liver can replace them, until the organ can no longer function adequately.
• Cancer – cirrhosis or some forms of hepatitis can make the liver more susceptible to primary cancer (cancer that originates in the liver).
• Gastrointestinal bleeding – the veins that normally travel through the liver may be blocked because of cirrhosis. These veins then bypass the liver and may travel along the stomach or oesophagus lining, where they may rupture and bleed.