Hepatitis, << `hehp` uh TY tihs, >> is a disease marked by inflammation of the liver and injury to that organ. The inflammation and injury may be acute (brief and severe). Or they may be chronic (lasting). Hepatitis has many causes. Some hepatitis results from misuse of alcohol and drugs. The most common cause of such drug-induced hepatitis is acetaminophen, a common pain reliever and fever reducer (see Acetaminophen). But most cases of hepatitis are caused by viruses and are called viral hepatitis.
Symptoms of viral hepatitis appear from two weeks to six months after exposure to the virus. The first symptoms are usually fatigue, poor appetite, and nausea. Other common symptoms include pain in the abdomen above the liver and a slight fever. After a few days, the person’s urine becomes dark. Jaundice (a yellowish discoloration of the skin) appears (see Jaundice). The jaundice and dark urine indicate the liver is not working properly. It is failing to adequately remove a reddish-yellow pigment called bilirubin from the blood.
Symptoms of viral hepatitis generally last two to six weeks. Severe cases can lead to liver failure and death. But most patients—even those with severe hepatitis—eventually recover completely. In some patients, the disease becomes persistent. This condition is called chronic hepatitis. People with chronic hepatitis may experience mild, vague symptoms of fatigue and poor appetite. Chronic hepatitis can lead to a liver disease called cirrhosis (see Cirrhosis). In some cases, it can lead to liver cancer.
There are five types of viral hepatitis. They are called hepatitis A, B, C, D, and E. Hepatitis types A, C, D, and E are caused by viruses with a core of ribonucleic acid or RNA (see RNA). The hepatitis B virus has a core of deoxyribonucleic acid or DNA (see DNA).
Hepatitis A
is highly contagious but rarely fatal. It is also called infectious hepatitis. Hepatitis A is common in less developed countries. Outbreaks often occur due to unsanitary conditions, such as contamination of food or the water supply. A protein called gamma globulin can prevent hepatitis A if given before or soon after exposure (see Gamma globulin). A vaccine that prevents hepatitis A is available and highly effective. It is recommended for high-risk groups, including international travelers and some military personnel.
Hepatitis B
is the best-known form of viral hepatitis. It can be severe. It may develop into chronic hepatitis and cirrhosis, especially among infants and children. Hepatitis B is spread by close personal or sexual contact with an infected person. It is also spread by exposure to infected blood. The disease once was commonly transmitted through transfusions of contaminated blood. However, tests that detect the virus in blood have largely eliminated this danger. Many infections occur through accidental prickings with hypodermic needles. A vaccine that prevents hepatitis B is available. Many public health experts recommend that all children be vaccinated. Doctors use a variety of drugs to treat chronic hepatitis B.
Hepatitis C
is the most common cause of chronic hepatitis. It is also a major cause of cirrhosis. Most cases result from using contaminated needles for injecting illegal drugs, tattooing, or body piercing. Hepatitis C may lead to chronic hepatitis, cirrhosis, or liver cancer. A blood test to detect this virus became available in 1990. Since that time, the infection is rarely transmitted through blood transfusions. Hepatitis C is often treated with a combination of interferon and another antiviral drug such as ribavirin, boceprevir, or telaprevir. Since 2013, three new drug treatments called simeprevir, sofosbuvir, and ledipasvir-sofosbuvir have been developed. The drugs cure up to 90 percent of patients with hepatitis C in as little as 8 to 24 weeks. However, the high cost of the new drugs has limited their use.
Hepatitis D
is a rare form of viral hepatitis. It only infects people who also have hepatitis B. Many cases of hepatitis D are fatal. Most chronic cases lead to cirrhosis. Hepatitis D is most common among intravenous drug users. Drug users can be infected by sharing needles.
Hepatitis E
often occurs in epidemics. It is linked to poor hygiene and contaminated water. It is particularly likely to lead to serious illness in pregnant women. The disease occurs worldwide. But it is more often seen in less developed countries.
