Symptoms and Complications
HAV has an incubation period (the time between infection and first symptoms) of 2 to 6 weeks. HBV only shows itself after 6 to 25 weeks.
Flu-like warning symptoms (called a prodrome) often appear about 3 to 10 days before liver symptoms arrive. Symptoms are low-grade fever, muscle aches, loss of appetite, nausea, vomiting, and fatigue. Smokers may find they suddenly dislike smoking. In HBV, these symptoms may be accompanied by joint pains and skin eruptions resembling urticaria (hives).
After this, the urine may darken, and jaundice may appear. In jaundice, the skin and the whites of the eyes take on a yellow tint. The inflamed liver is not able to perform its usual metabolic functions so that a substance called bilirubin (a byproduct from old red blood cells that also causes bile to be yellow) builds up in the body. Bile is a fluid secreted by the liver that contains cholesterol, bile salts, and waste products such as bilirubin.
Usually, you start to feel better when the jaundice arrives, even though you continue to look worse. The jaundice only lasts for about one week in HAV infection, or 2 weeks with HBV. After that you start to recover, and generally feel and look yourself again within a month. Rarely, HAV may come back briefly a month after that, but not for long. After recovering from hepatitis A, you're immune for life.
HBV, however, doesn't always get cleared out of the system. If this happens, you will probably not have any symptoms, but you'll be a lifelong carrier, and must take special precautions such as warning sexual partners. You may also suffer from chronic liver inflammation (chronic viral hepatitis) for the rest of your life.
Chronic hepatitis B is most likely to occur in infants (almost 100% chance if infected in the first year of life) and least likely in adults (5% overall chance). It can lead to cirrhosis (scarring) of the liver. It also increases the danger of developing liver cancer.