Hepatitis B is an infectious illness of the liver caused by the Hepatitis B virus. It is transmitted by exposure to infectious blood or body fluids. Risk factors include intravenous drug use, blood transfusion, sexual exposure, and being born in an area with a high incidence of Hepatitis B, such as Asia or Africa. Although most patients with acute Hepatitis B will make a complete recovery from the infection, the disease can become chronic and progress to cirrhosis of the liver or even liver cancer.
Symptoms of Hepatitis B infection may occur many weeks after exposure to the virus. This is known as the incubation period. Typical symptoms include fatigue, nausea, vomiting, yellowing of the skin and eyes (jaundice), dark urine, and light-colored stools. Chronic infection with Hepatitis B may be asymptomatic. Patients who develop end stage liver disease or cirrhosis may suffer complications such as confusion, abdominal swelling, gastrointestinal bleeding, and liver cancer.
Diagnosis of Hepatitis B is suspected when patients have appropriate symptoms and laboratory tests demonstrate abnormal liver enzymes in the blood. Diagnosis can be confirmed by looking for specific antibodies in the blood, which represent the body’s immune response to the infection. Sophisticated blood tests can be performed to detect and measure the virus in the bloodstream. A biopsy of the liver may be required to determine the degree of inflammation and scarring present. Imaging studies such as ultrasound, CT Scan, and MRI may be required to look for evidence of cirrhosis and to screen for the development of hepatocellular cancer.
Hepatitis B can be prevented through vaccination. Patients with acute Hepatitis B typically recover spontaneously and require supportive care. Patients with chronic Hepatitis B infection may be candidates for medical therapies to try and eliminate the virus from the body or suppress it to prevent progression to chronic liver disease and liver cancer. Patients with liver failure due to cirrhosis may ultimately require liver transplantation.