Hepatitis B is caused by the hepatitis B virus (HBV) that causes inflammation of the liver. The virus is found in the blood and can be transmitted when bodily fluids come in contact with a break in the skin or a mucous membrane, such as the vagina, rectum, or mouth. It may also be transmitted through shared syringes in intravenous drug abusers. Two types of hepatitis B infection exist: acute (shot-term) and chronic (long-term). Hepatitis B infection can present in different ways. Acute hepatitis B occurs a short time after exposure to the virus, usually between one and six months; an infection with HBV that lasts more than six months is considered chronic hepatitis B.
Asymptomatic
Some individuals are asymptomatic, which means they show no symptoms. The Centers for Disease Control and Prevention (CDC) state that most children under five years of age and newly infected immuno-suppressed adults are asymptomatic, whereas 30 to 50 percent of persons aged five years or more have initial signs and symptoms. In the other 50 to 70 percent of cases, otherwise healthy individuals have no symptoms and clear the infection without any further complications.
Flu-Like Symptoms
Like in most infections, hepatitis B can result in flu-like symptoms. Flu-like symptoms include fever, chills, cough, headaches and body aches. These symptoms cannot be used to diagnose hepatitis B because they are not exclusive to this virus.
Common Symptoms
Common symptoms of an acute HBV infection include fatigue, loss of appetite, nausea, vomiting and abdominal pain. Jaundice, a condition in which the skin and whites of the eyes turn yellow, may also develop. Dark urine and pale stools are symptoms of acute hepatitis B infection as well. These symptoms may also be found in a chronic hepatitis B infection.
Liver Damage
Many people with chronic hepatitis B may not display any symptoms and may be infected for up to 30 years. "Over time, approximately 15%--25% of people with chronic hepatitis B develop serious liver problems, including liver damage, cirrhosis, liver failure, or liver cancer," according to the CDC. Symptoms of liver damage include jaundice, abnormal bleeding, vomiting and seizures. Ascites is the retention of fluid in the belly causing it to swell and may also be present in liver damage.
Hepatic Encephalopathy
Hepatic encephalopathy is seen in chronic hepatitis B infections and is a consequence of liver impairment. Because the liver is unable to clear out toxic chemicals from the body, they may travel to the brain and damage normal brain cell function. Hepatic encephalopathy is characterized by excessive excitement, impaired mental ability, confusion and ultimately coma.
References
- "Pharmacotherapy: A Pathophysiologic Approach"; Joseph T. DiPiro, Rovert L. Talbert, Gary C. Yee; 2008
- Centers for Disease Control and Prevention: Hepatitis B FAQs for Health Professionals
- Centers for Disease Control and Prevention: Chronic Hepatitis B - Information on Testing
