Hepatitis
(Viral Hepatitis, A, B, C, D, E, G)

Medical Author:

Charles Patrick Davis, MD, PhD

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

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Medical Editor:

Jay W. Marks, MD

Jay W. Marks, MD

Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

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• Many illnesses and conditions can cause inflammation of the liver (hepatitis), but certain viruses cause about half of all hepatitis in people.
• Viruses that primarily attack the liver are called hepatitis viruses. There are several types of hepatitis viruses including types A, B, C, D, E, and possibly G. Types A, B, and C are the most common.
• Those at risk for viral hepatitis include workers in the health care profession, people with multiple sexual partners, intravenous drug abusers, and hemophiliacs. Blood transfusion is a rare cause of viral hepatitis.
• All hepatitis viruses can cause acute hepatitis.
• Viral hepatitis types B and C can cause chronic hepatitis.
• Symptoms of acute viral hepatitis include fatigue, flu-like symptoms, dark urine, light-colored stools, fever, and jaundice; however, acute viral hepatitis may occur with minimal symptoms that go unrecognized. Rarely, acute viral hepatitis causes fulminant hepatic failure.
• The symptoms of chronic viral hepatitis often are mild and nonspecific, and the diagnosis of chronic hepatitis often is delayed.
• Chronic viral hepatitis often requires treatment in order to prevent progressive liver damage, cirrhosis, liver failure, and liver cancer.
• Hepatitis infections can be prevented by avoiding exposure to viruses, injectable immunoglobulins or vaccines.

Hepatitis means inflammation of the liver. Many illnesses and conditions can cause inflammation of the liver, for example, drugs, alcohol, chemicals, and autoimmune diseases. Many viruses, for example, the virus of mononucleosis and the cytomegalovirus can inflame the liver. Most viruses, however, do not attack primarily the liver; the liver is just one of several organs that the viruses affect. When doctors speak of viral hepatitis, they are using the definition that means hepatitis caused by a few specific viruses that primarily attack the liver and are responsible for about half of all human hepatitis. There are several hepatitis viruses; they have been named types A, B, C, D, E, F (not confirmed), and G. As our knowledge of hepatitis viruses grows, it is likely that this alphabetical list will become longer. The most common hepatitis viruses are types A, B, and C. Reference to the hepatitis viruses often occurs in an abbreviated form. (For example, HAV, HBV, HCV represent hepatitis viruses A, B, and C, respectively.)

Hepatitis viruses replicate (multiply) in the liver cells. Newly-produced viruses are released into the blood stream where they can be spread to other organs or to other persons exposed to the infected blood.

1. The liver helps purify the blood by changing harmful chemicals into harmless ones. The source of these chemicals can be external, such as medications or alcohol, or internal, such as ammonia or bilirubin. Typically, these harmful chemicals are broken down into smaller chemicals or attached to other chemicals that then are eliminated from the body in the urine or stool.
2. The liver produces many important substances, especially proteins that are necessary for good health. For example, it produces albumin, the protein building block of the body, as well as the proteins that cause blood to clot properly.
3. The liver stores many sugars, fats and vitamins until they are needed elsewhere in the body.
4. The liver builds smaller chemicals into larger, more complicated chemicals that are needed elsewhere in the body. An example of this type of function is the manufacture of cholesterol.

When the liver is inflamed, it does not perform these functions well, which brings about many of the symptoms, signs, and problems associated with any type of hepatitis. Each viral type has both articles and books describing the details of infection with that specific virus. This article is designed to give the reader an overview of the predominant viruses that causes viral hepatitis and should help the reader choose the subject(s) for more in depth information.