There are five types of hepatitis viruses which cause inflammation of the liver. These viruses are designated as hepatitis A, B, C, D or E, with the hepatitis C virus (HCV) being the more common cause of viral hepatitis. A person may be infected by these viruses through various methods of transmission. This almost always involves contact with the body fluids (blood, saliva or semen) or excrement (feces), either through direct contact or ingestion of contaminated food or water.
Two other types of viral hepatitis that are not often discussed under viral hepatitis is hepatitis G and hepatitis X. Hepatitis G occurs with other viral infections like HIV but does not cause any disease in humans. Hepatitis X is used to denote an acute viral hepatitis that cannot be associated with the hepatitis viruses A to E.
The hepatitis viruses belong to different groups of viruses, vary in size and structure but all have one common feature in that it specifically targets the liver cells (heptocytes) and causes inflammation of the liver tissue and even death of these cells. There are other viruses that may also cause hepatitis but usually do not specifically target the liver cells. Read more on Causes of Hepatitis.
Symptoms of Viral Hepatitis
Viral hepatitis is usually asymptomatic in the early stages meaning that no symptoms are present. This asymptomatic period may vary depending on the incubation period of the specific hepatitis virus as discussed below. Symptoms appear in the prodromal period of acute infection and may then resolve spontaneously. Even chronic hepatitis may be asymptomatic until cirrhosis sets in.
The earliest stages may be characterized by non-specific symptoms such as :
- Muscle pain (myalgia)
- Joint pain (arthralgia)
- Loss of appetite
- Fever (not always and may appear a later)
Eventually this may be followed by symptoms such as :
- Abdominal discomfort or pain *
* Right upper quadrant abdominal tenderness and mild enlargement of the liver may be detected upon palpation. Refer to liver pain location for more information.
The late stages of infection may present with the following symptoms :
The symptoms tend to last for 3 to 6 weeks but may vary slightly depending on the type of virus but can persist for up to 6 months in HBV infection.
Viral Hepatitis Incubation Periods
- Hepatitis A
- Incubation period = 2 to 4 weeks (may be up to 6 weeks, average 1 month)
- Hepatitis B
- Incubation period = 4 to 20 weeks (1 to 4 months, average 3 months)
- Hepatitis C
- Incubation period = 4 to 12 weeks (can be as early as 2 weeks or as late as 24 weeks)
- Hepatitis D
- Incubation period = 6 to 9 weeks (depends on HBV infection)
- Hepatitis E
- Incubation period = 3 to 8 weeks (average 40 days)
Complications of Viral Hepatitis
The complications may depend on the type of hepatitis virus and relapses.
- Acute liver failure
- Chronic liver disease
- Aplastic anemia
- Cholestatic hepatitis