The word hepatitis comes from the Ancient Greek word hepar (root word hepat) meaning 'liver', and the Latin itis meaning inflammation.
Hepatitis means injury to the liver with inflammation of the liver cells. There are five main types of hepatitis and the type is commonly determined by a laboratory test.
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Fast facts on hepatitis
Here are some key points about hepatitis. More detail and supporting information is in the main article.
- The five main types of hepatitis are caused by viruses.
- Globally, around 250 million people are affected by hepatitis C and 300 million people are estimated to be hepatitis B carriers.
- Hepatitis A is caused by consuming contaminated food or water.
- Hepatitis B is a sexually transmitted disease.
- Hepatitis C is commonly spread via direct contact with the blood of a person who has the disease.
- A person can only become infected with hepatitis D if they are already infected with hepatitis B.
- Person can become infected with the hepatitis E virus (HEV) by drinking contaminated water.
- Hepatitis that cannot be attributed to one of the viral forms of the disease is called hepatitis X.
- Hepatitis G is another type of hepatitis caused by a specific virus (HGV).
- The initial symptoms of hepatitis are similar to those of flu.
Hepatitis and the liver
The liver is the largest gland in the human body. It weighs approximately 3 lb (1.36 kg). It is reddish brown in color and is divided into four lobes of different sizes and lengths. It is also the largest internal organ (the largest organ is the skin). It is below the diaphragm on the right in the thoracic region of the abdomen. Blood reaches the liver through the hepatic artery and the portal vein. The portal vein carries blood containing digested food from the small intestine, while the hepatic artery carries oxygen-rich blood from the aorta.
The liver is made up of thousands of lobules, each lobule consists of many hepatic cells - hepatic cells are the basic metabolic cells of the liver.
The liver has a wide range of functions, including:
Most liver damage is caused by 3 hepatitis viruses, called hepatitis A, B and C.
- Detoxification (filters harmful substances form the blood, such as alcohol)
- Stores vitamins A, D, K and B12 (also stores minerals)
- Protein synthesis (makes certain amino acids - the building blocks of proteins)
- The production of biochemicals needed for digestion, such as bile
- Maintains proper levels of glucose in the blood
- Produces 80% of your body's cholesterol (cholesterol is vital)
- The storage glycogen (also converts glucose to glycogen)
- Decomposing red blood cells
- Synthesizing plasma protein
- The production of hormones
- Produces urea (the main substance of urine).
Hepatitis can heal on its own with no significant consequence, or it can progress to scarring of the liver. Acute hepatitis lasts under six months, while chronic hepatitis lasts longer.
Most liver damage is caused by 3 hepatitis viruses, called hepatitis A, B and C. However, hepatitis can also be caused by alcohol and some other toxins and infections, as well as from our own autoimmune process (the body attacks itself).
About 250 million people globally are thought to be affected by hepatitis C, while 300 million people are thought to be carriers of hepatitis B.
Not all forms of hepatitis are infectious. Alcohol, medicines, and chemical may be bad for the liver and cause inflammation. A person may have a genetic problem, a metabolic disorder, or an immune related injury. Obesity can be a cause of liver damage which can lead to inflammation. These are known as non-infectious, because they cannot spread form person-to-person.
On the next page we look at the individual types of hepatitis (hepatitis A, B, C, D, E, X and G) and their signs and symptoms. On the final page we discuss the available treatments and how hepatitis can be prevented.