Hepatitis, or inflammation of the liver, has many causes, including several viruses, a host of chemicals and drugs, bacteria, diseases of the immune system, inherited factors, and herbs. For most of the population "hepatitis" refers to that caused by viruses, the major concern of this book, although many of the nonviral types also are mentioned. Every year, about 140,000 new cases of hepatitis A occur in the United States, and perhaps over a million around the world. Because some of those who are infected do not become ill, the statistics are perhaps ten times greater than the number recognized. Fortunately, this strain is not chronic (defined as disease that lasts longer than six months). Hepatitis B infects about 1,250,000 in the U.S. and about 350,000,000 worldwide. Hepatitis C, unique in many ways and virtually always chronic, has produced some 4,000,000 cases in the U.S. About 1.6 percent of the population has been infected at some time, and at least seventy-five percent in this group retain the live virus in their blood. A fourth virus, hepatitis D, is uncommon in the United States. Not only debunking fearful myths but also providing helpful particulars on how to avoid the risks, Understanding Hepatitis furnishes the reader with a better grasp of the disease. In comprehensible terms, this book includes a historical overview, a discussion of symptoms and treatments, and a report on current research.