Hepatitis A, B, and C: How They Differ
Types of hepatitis
Hepatitis means inflammation of the liver. It impairs the ability of the liver to carry out its normal functions and, if it becomes chronic, can lead to cirrhosis (extensive scarring) of the organ or liver cancer. The infectious forms of hepatitis in the U.S. are usually caused by three viruses, called A, B, and C. (Two other viral forms, D and E, occur primarily in the developing world.)
There are also noninfectious forms of hepatitis caused, for instance, by toxic substances (notably alcohol) and excessive use of certain medications (notably acetaminophen) and even some herbal dietary supplements. Another common type of hepatitis, called non-alcoholic steatohepatitis (NASH), is seen in some people who have nonalcoholic fatty liver disease (NAFLD), which is a spectrum of disorders occurring when the liver has trouble processing fat, leading to fat accumulation in liver tissue.
Hepatitis signs and symptoms
Exposure to hepatitis can cause acute infection, producing symptoms such as fever, loss of appetite, nausea, fatigue, diarrhea, abdominal pain, dark urine, and jaundice, typically lasting six to eight weeks. Or, as is often the case, there can be no symptoms at all, though the infected person can still transmit the virus. Whether they cause initial symptoms or not, hepatitis B and C can remain in the body (sometimes for life), resulting in chronic infection that can eventually cause serious disease, notably cirrhosis and liver cancer.
It’s easy to be confused about the forms of viral hepatitis, which differ in how they spread, how they affect the liver, whether they are likely to become chronic, and whether there are vaccines (only for A and B). See at the end of the page for more details.
Vaccines and tests for hepatitis
- The hepatitis A vaccine should be given to all children at age one; people who travel to Latin America, Africa, Southeast Asia, or other areas where hepatitis A is common; men who have sex with men; and those with chronic liver disease (including hepatitis B or C and NAFLD).
- The hepatitis B vaccine should be given to all newborns; unvaccinated older children; people with multiple sex partners; men who have sex with men; people with chronic liver disease, diabetes, or HIV; health-care workers; drug users who share needles or cocaine straws; and travelers to areas with high rates of infection. If your sexual partner is infected, you should be vaccinated. There is also a combined vaccine for hepatitis A and B. Ideally, everybody should be vaccinated against both A and B.
- Get tested for hepatitis B if you are pregnant (if you test positive, your child should receive a special injection at birth to prevent infection). You should also be tested if you have multiple sex partners, have HIV, have ever shared injectable-drug needles or cocaine straws, or are about to start taking immunosuppressive drugs. Unvaccinated people born in regions with high infection rates should also be tested, as should U.S.-born people whose parents were born in such regions.
- Get tested for hepatitis C if you were born between 1945 and 1965 or had a blood transfusion before 1992. Also get tested if you have ever shared injectable-drug needles or cocaine straws, have HIV, or have signs of liver disease. Unfortunately, there is no vaccine for hepatitis C.
Steps to prevent hepatitis
- Wash your hands. Always wash with soap and water after using the toilet, after changing diapers, before handling food, and before eating. This helps stop the spread of hepatitis A and many other diseases.
- Cook foods adequately. Hepatitis A can spread via raw or undercooked food (especially shellfish) and contaminated water.
- Use condoms, which significantly reduce the risk of hepatitis B and C. This is particularly important if you know that your partner is infected or if you have multiple partners.
- Never share unsterilized needles for any purpose. If you are getting your body pierced or tattooed or are receiving acupuncture, make sure the needles are brand new or have been properly sterilized.
- Don’t share toothbrushes or instruments that can puncture the skin, such as razors or manicure tools.
- Avoid excessive alcohol intake. Liver damage, including hepatitis (in this case known as alcoholic steatohepatitis), is just one of many toxic results of heavy drinking.
- Reduce the risk of NAFLD and its progression to NASH by maintaining a desirable weight (via diet and exercise) and controlling blood cholesterol, triglycerides, and blood sugar levels. Cut down on foods and beverages sweetened with high-fructose corn syrup or sucrose (table sugar), which are both major sources of fructose. Studies have linked fructose, in particular, to NAFLD and NASH.
- Don’t take too much acetaminophen. Overdosing on acetaminophen (Tylenol, plus generics) is a leading cause of liver damage in the U.S. It’s easy to get harmful amounts, since this pain reliever is found in many headache and cold/flu remedies and other over-the-counter drugs, as well as in some prescription pain relievers. Adults shouldn’t take more than 3,000 milligrams a day from all sources (equal to six Extra-Strength Tylenol tablets). Read ingredients lists carefully. Drinking alcohol while taking acetaminophen greatly increases the risk of liver damage.
Hepatitis A, B, and C: How They Differ
The three main types of viral hepatitis differ in how they spread, how they affect the liver, whether they are likely to become chronic, and whether there are vaccines to prevent them. Here are the details on each.
CHRONIC: No.HOW TRANSMITTED: Fecal matter from an infected person contaminating food or water.
COMMENT: Usually causes mild to moderate symptoms lasting several weeks; often no symptoms. Most people recover completely without treatment. Rarely causes liver failure or death. Confers lifelong immunity.
CHRONIC: 5 to 10 percent of infected people over age 5.HOW TRANSMITTED: Blood, semen, and other body fluids, usually via unprotected sex or shared needles or cocaine straws. Also mother to fetus.
COMMENT: Acute symptoms, when they occur, are generally mild. People with chronic infection often remain asymptomatic until they develop cirrhosis or liver cancer.
CHRONIC: 80 percent of cases.HOW TRANSMITTED: Blood, usually via transfusions before 1992 or shared needles or cocaine straws. Sexual transmission rare, but risk rises with multiple partners or concomitant HIV infection.
COMMENT: Only about 25 percent of newly infected people develop acute symptoms. At least half of people with chronic infection don’t know it because it can take decades for signs or symptoms to develop, at which point liver damage can be severe. About 5 to 20 percent develop cirrhosis or liver cancer.