Acute and chronic hepatitis

Hepatitis can be divided into two subgroups according to its duration: acute hepatitis and chronic hepatitis. The acute stage can last from several weeks to several months. In some people, hepatitis B becomes an illness that lasts a long time, a condition called chronic hepatitis. Other people recover from the infection and have no long-lasting problems.

Chronic hepatitis occurs when the liver has been damaged from the acute illness and doesn't recover. Chronic hepatitis develops in 10% to 20% of people who have hepatitis B. Cirrhosis of the liver develops in 20% of cases of chronic hepatitis. Cirrhosis occurs when the liver cells die and are replaced by scar tissue and fat. The liver stops working and can't cleanse the body of wastes. People in the early stages of cirrhosis may not have symptoms. When cirrhosis gets worse, symptoms begin. They may include weight loss, fatigue, jaundice, nausea, vomiting and loss of appetite. Cirrhosis can lead to liver failure (the liver stops working) and liver cancer.

A healthy liver

A liver affected by cirrhosis

The time between the acute illness and signs of chronic hepatitis varies. It may take a short time, or it may take years after the acute infection before chronic hepatitis develops.

In 20 percent of cases, the person recovers from the illness, but the virus remains in their blood, capable of infecting other people.

Some people infected with HBV or HCV become chronic carriers of the virus, although they may have no symptoms. There are an estimated 300 million carriers worldwide. Children are at greatest risk. About 90 percent of babies who become infected at birth with HBV, and up to half of youngsters who are infected before age 5, become chronic carriers.