Hepatitis B is an infectious disease caused by the hepatitis B virus (HBV) which affects the liver. It can cause both acute and chronic infections. Many people have no symptoms during infection. Some develop a rapid onset of sickness with vomiting, yellow skin, feeling tired, dark urine and abdominal pain. It may take 30 to 180 days for symptoms to begin. Cirrhosis and liver cancer may eventually develop. These complications results in the death of 15 to 25% of those with chronic disease.
About a third of the world population has been infected at one point in their lives, including 240 million to 350 million who have chronic infections.Over 750,000 people die of hepatitis B each year.