Viral Hepatitis can be defined as the constellation of symptoms and signs resulting from hepatic inflammation and hepatic cell necrosis. If the insult is acute and occurs in a previously asymptomatic individual, the term acute hepatitis can be applied. The most common causes of acute hepatitis are viruses, toxins, and alcohol. Occasionally other disease entities such as Wilson disease, leukemias, and lymphomas with acute infiltration of the liver may give rise to a clinical picture of acute hepatitis. Viruses, however, are the major etiologic agents of acute liver injury. Systemic infection with several viruses results in hepatic inflammation and cell death. Viruses that cause hepatitis have been classified as hepatitis A (HAV), B (HBV), C (HCV), delta (HDV), and E (HEV). However, in some individuals, infection with the Epstein-Barr virus (EBV) or cytomegalovirus (CMV) also results in acute hepatitis. In most patients, acute viral hepatitis presents as an acute illness characterized by the abrupt onset of malaise, fever, anorexia, nausea, headache, abdominal discomfort, and pain. Jaundice, itching, dark-colored urine, and light-colored stools often cause the patient to seek medical attention. At this stage, the disease caused by different viruses is usually indistinguishable, and serologic studies may provide the only means of identification.