There are six main types of viral hepatitis: A, B, C, D, E, and G. The three main types in the United States are hepatitis A, B, and C. Vaccines can prevent some viral hepatitis infections.
Hepatitis is an inflammation of the liver. It usually results from a viral infection, but drugs, toxins, and certain diseases, including autoimmune diseases, may also cause the condition.
Scientists have only recently discovered hepatitis G (HGV), and they know less about it than other forms of hepatitis.
The following table shows the main types of hepatitis:
|A (HAV)||consuming food or drink contaminated with the feces of someone with the infection||nausea, fatigue, dark urine, vomiting, fever, jaundice, and anorexia|
|B (HBV)||making contact with the body fluids of a person with the infection — usually from the woman to the fetus at birth, but occasionally from using contaminated needles or having sex without a condom||unease, fatigue, anorexia, and mild illness|
|C (HCV)||making contact with blood containing the virus — mostly spread through contaminated needles of IV drug users||80% of people have no symptoms, but others have unease, fatigue, and anorexia|
|D (HDV)||same as HBV||unease, fatigue, anorexia, and mild illness|
|E (HEV)||usually through consuming undercooked meat or food or drink contaminated with the feces of someone with the infection, but occasionally from a pregnant woman to a fetus||mild illness|
|G (HGV)||through blood containing the virus||mild infection, but most people have no symptoms|
The symptoms of hepatitis may be mild, but the condition can lead to severe complications. For example, each type of hepatitis can cause fulminant hepatic failure (FHF), which affects the liver.
Hepatitis may be acute or chronic. Acute hepatitis is short-term, lasting less than 6 months. Chronic hepatitis is long-term, lasting more than 6 months. Hepatitis C is the most common cause of chronic hepatitis.
Vaccines and vaccine schedules depend on the type of hepatitis.
The HAV vaccine can prevent hepatitis A. This shot is routine for infants between the ages of 12 and 23 months. Unvaccinated children older than 23 months, adolescents, and adults should also have this shot.
A doctor will administer the vaccine over two doses, with 6 months between them.
The HBV vaccine is a routine shot that usually immunizes people for life. A person will typically have the first dose at birth and complete the schedule at 6 months old.
An unvaccinated child or adolescent below the age of 19 should also have the shot. Some adults who are not vaccinated should also receive the vaccine — for example, those traveling to areas where hepatitis B is common.
A doctor may administer the hepatitis B vaccine in two, three, or four doses.
The HBV vaccine can prevent hepatitis D, which is a coinfection of hepatitis B. However, the vaccine will not protect a person from hepatitis D if they already have chronic hepatitis B.
There is currently no vaccine for hepatitis G.
An autoimmune disease causes hepatitis when the immune system attacks the liver. Autoimmune hepatitis is often genetic in origin, but factors such as viral infection or drug use may trigger the condition.
The most common symptoms are:
However, some people may not experience any symptoms.
Alcoholic hepatitis begins when the liver is unable to cope with the level of toxins due to a high alcohol intake.
Medications are available to treat hepatitis.
A person with acute hepatitis C may undergo interferon therapy.
Pegylated interferon (PEG-IFN), a variation of standard interferon therapy, can treat:
Experts have found that direct-acting antivirals can effectively treat more than 90% of cases of chronic hepatitis C. Treatment schedules last 8–12 weeks.
A person may use the antiviral medication ribavirin to treat hepatitis E, but it is not always effective.
There are various ways of contracting hepatitis, depending on the type. Contracting a viral form of hepatitis depends on the mode of transmission, which the table above shows.
A person may sometimes contract hepatitis nonvirally. In autoimmune hepatitis, the immune system attacks the liver cells. Ingesting substances that contain toxins, such as alcohol, can also induce some types of hepatitis.
A doctor may use a blood test to diagnose viral hepatitis.
A healthcare professional will check a person’s blood for:
- HAV-specific immunoglobulin G (IgM) antibodies to diagnose HAV
- the surface antigen HBsAg to diagnose HBV
- anti-HCV antibodies to diagnose HCV
- high immunoglobulin G (IgG) and anti-HDV immunoglobulin M (IgM) levels to diagnose HDV
- virus–specific IgM antibodies to identify HEV
To diagnose autoimmune hepatitis, a doctor may consider:
- medical history
- blood and imaging tests
- a liver biopsy
- a physical examination
They may suggest additional tests to confirm the condition.
The main complications of hepatitis affect the liver, but the disease can also lead to:
- leg, ankle, and foot swelling
- blood in the feces and vomit
Problems for the liver include fibrosis, cirrhosis, loss of function, and cancer. Without proper treatment, hepatitis can be life threatening.
People should see a doctor if they have not had the vaccine and believe that they may have had exposure to hepatitis.
A pregnant woman should undergo screening for HBV to enable healthcare providers to take preventive measures to protect the fetus, if necessary.
The outlook for people with hepatitis depends on the type, the individual, and the treatment that they receive.
Some people make a full recovery either with or without treatment. However, for others, hepatitis will be a lifelong condition.
If a person with alcoholic hepatitis stops consuming alcohol for 6–12 months, they may start to recover within a few years.
If hepatitis does not respond to treatment, the person may require a liver transplant.
Preventive measures are the most effective way of avoiding viral hepatitis.
A person can lower the chances of contracting hepatitis by drinking only clean or treated water and maintaining hand and personal hygiene by washing regularly.
When traveling to an area where hepatitis is common, people should avoid raw seafood and shellfish and only consume fruits or vegetables that are cooked or peeled.
A person with an autoimmune disease should undergo testing for autoimmune hepatitis early on so that they can begin a long-term treatment plan if necessary.
Abstaining from alcohol can prevent alcoholic hepatitis.
Hepatitis is an inflammation of the liver. There are different types of hepatitis, including viral and noninfectious forms.
Hepatitis may be acute, lasting fewer than 6 months, or chronic, if it lasts longer.
The symptoms of hepatitis are often mild, but complications may be severe if the person does not receive treatment.
Cases of hepatitis in the U.S. have declined significantly over recent years due to preventive measures, such as vaccines. However, the disease is still prevalent and can have severe consequences without treatment.