Hepatitis B is an infectious disease of the liver caused by the hepatitis B virus (HBV). The hepatitis B virus interferes with liver function by replicating in the liver cells. Hepatitis B can take on an acute or chronic form. Most cases of hepatitis B are acute and the disease is cleared from the body without intervention. However, in some people the hepatitis B infection is not cleared from the body and becomes chronic, leading to irreversible liver damage and even death.
There are two types of hepatitis B:
Acute: a short-term illness occurring within six months of exposure to the hepatitis B virus. Symptoms typically last several weeks but can last as long as six months. Most healthy adults and children over the age of five who contract hepatitis B get better without treatment.
Chronic: a long-term illness occurring when the hepatitis B virus remains in the patient’s body. Chronic hepatitis B is a serious disease that can result in serious health problems. Children are more likely to develop chronic hepatitis B than adults.
Without treatment, chronic hepatitis B can cause liver cancer or severe liver damage that leads to liver failure. While there is no cure for hepatitis B, a vaccination can prevent the disease. For individuals already infected, certain precautions can prevent transmitting the hepatitis B virus to others.
Hepatitis B is a communicable disease spread by direct contact with infected body fluids such as blood, semen, and saliva. Common transmission methods include sexual contact, needle sharing or needle stick accidents. Hepatitis B can also be passed from an infected mother to her newborn baby at birth. The hepatitis B virus is not spread by casual contact.
Symptoms that may appear six weeks to six months after exposure include fatigue, poor appetite, fever, stomach pain, nausea, and vomiting. The urine may become dark in color, and the patient may develop a yellowing of the skin and eyes (jaundice).
It is not uncommon for hepatitis B to cause no symptoms at all, or for there to be no symptoms until damage to the liver has occurred. Adults are more likely than children to exhibit hepatitis B symptoms.
Diagnosis of hepatitis B is done by blood test. If hepatitis B is found, additional blood tests may be ordered to assess liver health and to measure the severity of the infection. A liver biopsy may also be done to examine the liver tissue for damage.
Because most cases of hepatitis B are self-clearing, the disease is not usually treated unless it becomes chronic. Chronic hepatitis B may be treated with antiviral medicines to help slow or stop liver damage. Chronic hepatitis B patients are monitored closely with regularly scheduled blood tests. A liver transplant may be necessary if liver damage is severe or the disease progresses to liver failure.