or Life Depends On The Liver!
The liver is the largest organ in the body, weighing 1-1.5 kg and hidden mostly by the lower right ribcage. Its shape is determined by the cavity available in the upper right part of the abdomen, between the diaphragm and the rib margin. It is one of only two organs (the other is the pituitary gland) to have two blood supplies, the liver receiving blood from the hepatic arteries[20%] and the portal vein [80%](carrying blood from the intestines). The liver makes and/or breaks down proteins, sugars and fats, stores nutrients absorbed from the intestines and removes toxins from the blood. It is the powerhouse, recycling and disposal plant of the body. Life literally is not possible without the liver.
There are many causes of liver disease, including alcohol, viral hepatitis (for example Hepatitis B, C1 and the glandular fever virus EBV2), autoimmune diseases, poisons/drugs (for example paracetamol in overdose, some antibiotics, arthritis drugs) and inherited disorders. Hepatitis A NEVER causes chronic problems or cirrhosis. The most common cause in Western countries is alcohol - worldwide is Hepatitis B (often transmitted from mother to foetus).Blockage of the biliary system3 and haemolytic anaemia4 cause jaundice as well.
The Liver's Normal Function
The liver receives the blood from the gut after a meal and turns sugar(glucose) into glycogen (storage molecule). This is turned back into glucose when required keeping blood glucose levels stable. The liver also makes proteins (mostly blood proteins eg clotting factors and albumin, and hormones), bile acids (essential for fat digestion and vitamin absorption) and converts excess protein into energy. The breakdown of haemoglobin, cholesterol and proteins all occur at least partly in the liver. Water-soluble toxins and waste products can be eliminated via the kidneys in the urine, but non-water soluble toxins need to be chemically modified by the liver to allow this process to occur. The liver has many enzymes with a wide specificity to tackle both waste products of the body and xenobiotics (chemicals not produced by the body).
The Diseased Liver
The initial response of the liver to disease is inflammation and fatty change. Heavy drinking will cause alcoholic hepatitis. Prolonged or severe inflammation leads to cirrhosis (scarring of the liver). When a section of liver is removed the liver will regenerate, but scarring in cirrhosis stops this regeneration and so the damage is irreversible. The most obvious sign of liver disease is jaundice, where the skin and whites of the eyes (sclera) are yellow. Other symptoms include itching, nausea and pain in the right upper area of the abdomen. The complications of liver cirrhosis include: lack of albumin causing swollen legs and abdomen; lack of clotting factors causing easy bruising and internal haemorrhages (haematomas); impaired mental state from low blood sugar and toxins(acting like morphine and sleeping tablets) normally removed by the liver; and cancer of the liver (hepatoma). Death is usually from infection from a suppressed immune system or vomiting blood from abnormal vessels in the oesophagus (varices). The only treatment for liver failure is transplantation
Liver disease is often first detected because of abnormal liver blood tests, often called liver function tests ( LFTS, although they are not actually a measure of liver function). Abnormal albumin and blood clotting tests demonstrate abnormal liver function. The pattern of the abnormalities of LFTs points to whether the problem is the liver, haemolytic anaemia or the biliary system. Blood tests can diagnose viral hepatitis and autoimmune liver diseases. Iron and copper levels on blood tests check for iron overload (haemachromatosis) and copper overload (Wilson's disease), both inherited diseases that can cause cirrhosis. An ultrasound will show blockage of the bile duct, fatty liver, cirrhosis and liver tumours. A liver biopsy may be necessary to examine the liver under the microscope, look for iron or copper, or determine the amount of virus present.
The main aim of treatment of liver disease is to prevent cirrhosis. Obviously alcohol consumption must stop. Hepatitides B and C can be treated with antiviral drugs. Where the patient's immune system is attacking the liver powerful suppressants of the immune system are given. N-acetylcysteine is given to prevent damage from paracetamol overdoses. Iron or copper overload can be treated with chelating agents that help the body to eliminate the excess heavy metals.
Treatment of cirrhosis involves preventing complications eg drugs to prevent bleeding from varices, ensuring good nutrition and monitoring for liver cancer.