Definition: what is hepatitis? Hepatitis is an inflammation of the liver, most commonly from a viral source. It is known as mild hepatitis during the contamination period and then chronic hepatitis if the disease persists for six months after the infection. Depending on the cause, hepatitis can be quite serious. Among the most serious complications, there is fulminant hepatitis (extreme liver failure), fibrosis, cirrhosis or liver cancer. Types of hepatitis There are two main families of hepatitis: viral hepatitis and non-viral hepatitis. - Viral hepatitis: As the name suggests, viral hepatitis is an infection caused by a virus. From the moment that it affects the liver, it affects the liver cells known as hepatocytes and multiplies. Viral hepatitis is divided into many forms depending on the virus responsible for the infection and the way the person was infected. Hepatitis A: This is the least serious of the viral hepatitis’. This is because it doesn’t develop into a chronic form and doesn’t generally cause complications. The hepatitis A virus is mainly spread by ingesting water or food that has been contaminated by the stool of an infected person and it is common in countries with bad sanitary conditions. Hepatitis B: This is the most common type of hepatitis. The hepatitis B virus (HBV) is mainly spread by contact with blood or by sexual intercourse with an infected person. It is very contagious, being between 50 to 100 times more infectious than the AIDS virus. Hepatitis C: Contamination by this virus is mainly done by the blood stream. In more than half of cases, hepatitis C evolves into chronic hepatitis which causes cirrhosis 20% of the time and liver cancer in rarer cases. The hepatitis C virus (HCV) is one of the most resistant strains of the virus. Hepatitis D: This virus can’t affect people who are already infected by the HBV virus because the hepatitis D virus needs to be able to multiply. Contamination also happens in the same way as the HBV virus. Hepatitis E: Like hepatitis A, it is mild in most cases, doesn’t develop into chronic hepatitis and is spread through the airways. - Non-viral hepatitis: The non-viral hepatitis viruses most commonly come from a toxic source. They occur following the ingestion of a substance that is toxic to the liver. Alcoholic hepatitis: This is hepatitis caused by consuming too much alcohol. The toxicity of the alcohol attacks the liver cells which is the cause of the inflammation. The major form of the disease is rare but its development can have serious consequences. Drug-induced hepatitis: Abusing some drugs which contain hepatic toxicity (such as paracetamol) can lead to a deterioration of the state of the liver. Autoimmune hepatitis: The cause of this strain is unknown. It is characterized by a presence of auto-antibodies and there are two types. Type 1 autoimmune hepatitis is accompanied by anti-actin and anti-nuclear antibodies whereas type 2 autoimmune hepatitis is characterized by anti-LKM antibodies (liver kidney microsomes). These types can evolve into cirrhosis. Symptoms of hepatitis It is impossible to determine the type of hepatitis based solely on the symptoms shown. This is because whatever its origin, hepatitis is symptomless in most cases. Nevertheless, there are clinical signs that are non-specific to the disease such as fever, fatigue, a loss in appetite, nausea, vomiting, a dark colouring of the urine, abdominal pains or icterus (jaundice).