What is hepatitis?
Hepatitis is the inflammation of the liver, resulting in liver cell damage and destruction. Hepatitis is the Latin word for liver inflammation. It is characterised by the destruction of a number of liver cells and the presence of inflammatory cells in the
liver tissue. Hepatitis can be caused by diseases that primarily attack the liver cells. It can also arise as a result of a disease such as mononucleosis.
The liver is the largest organ in the body, occupying the entire upper right quadrant of the abdomen. It performs over 500 vital functions. It processes all of the nutrients the body requires, including proteins, glucose, vitamins, and fats. The liver manufactures bile, the greenish fluid stored in the gall bladder that helps digest fats. One of the liver's major contributions to life is to render harmless potentially toxic substances, including alcohol, ammonia, nicotine, drugs, and harmful by-products of digestion. Old red blood cells are removed from the blood by the liver and spleen, and the iron contained in them is recycled to the bone marrow to make new red blood cells.
Damage to the liver can impair these and many other processes. Hepatitis varies in severity from a self-limited condition with total recovery to a life-threatening or life-long disease. It can occur from many different causes. In the most common hepatitis cases, specific viruses incite the immune system to fight off infections (called viral hepatitis). Specific immune factors become over-produced that cause injury. Hepatitis can also result from an autoimmune condition, in which abnormal immune factors attack the body's own liver cells. Inflammation of the liver can also occur from medical problems, drugs, alcoholism, chemicals, and environmental toxins.
Hepatitis may resolve quickly (acute hepatitis), or cause long-term disease (chronic hepatitis). In some instances, progressive liver damage or liver failure may result. Acute hepatitis can begin suddenly or gradually, but it has a limited course and rarely lasts beyond one or two months. Usually there is only spotty liver cell damage and evidence of immune system activity, but on rare occasions, acute hepatitis can cause severe, even life-threatening, liver damage. The chronic forms of hepatitis persist for prolonged periods. Chronic persistent hepatitis is usually mild and nonprogressive or slowly progressive, causing limited damage to the liver. Chronic active hepatitis involves extensive liver damage and cell injury beyond the portal tract.
Most cases of hepatitis are caused by viruses that infect liver cells and begin replicating. They are defined by the letters A through G: Hepatitis A, B, and C are the most common viral forms of hepatitis. Investigators are still looking for additional viruses that may be implicated in hepatitis unexplained by the current known viruses. Other hepatitis viruses include hepatitis E and hepatitis G. Like hepatitis A, hepatitis E is caused by contact with contaminated food or water. It is not serious except in pregnant women, when it can be life threatening. Hepatitis G is always chronic with probably the same modes of transmission as hepatitis C, but to date it does not appear to have serious effects.
Ethanol, mostly in alcoholic beverages, is an important cause of hepatitis. Usually alcoholic hepatitis comes on after a period of increased alcohol consumption. Alcoholic hepatitis is characterized by a variable constellation of symptoms, which may include feeling unwell, enlargement of the liver, development of fluid in the abdomen ascites, and modest elevation of liver blood tests. Alcoholic hepatitis can vary from mild with only liver test elevation to severe liver inflammation with development of jaundice, prolonged prothrombin time, and liver failure. Severe cases are characterized by either obtundation or the combination of elevated bilirubin levels and prolonged prothrombin time; the mortality rate in both categories is 50% within 30 days of onset.
Non-alcoholic steatohepatitis (NASH) is a type of hepatitis which resembles alcoholic hepatitis on liver biopsy (fat droplets, inflammatory cells, but usually no Mallory's hyalin) but occurs in patients who have no known history of alcohol abuse. NASH is more common in women and the most common cause is obesity or the metabolic syndrome. A related but less serious condition is called "fatty liver" (steatosis hepatis). A liver biopsy for fatty liver shows fat droplets throughout the liver, but no signs of inflammation or Mallory's hyalin. Anomalous presentation of human leukocyte antigen (HLA) class II on the surface of hepatocytes - possibly due to genetic predisposition or acute liver infection - causes a cell-mediated immune response against the body's own liver, resulting in autoimmune hepatitis.
Autoimmune chronic hepatitis accounts for about 20% of all chronic hepatitis cases. Like other autoimmune disorders, this condition develops because a genetically defective immune system attacks the body's own cells and organs (in this case the liver) after being triggered by an environmental agent, probably a virus. Autoimmune hepatitis has a prevalence of 1-2 per 1000. As with most other autoimmune diseases, it affects women much more often than men (8:1). Liver enzymes are elevated, as is bilirubin. Autoimmune Hepatitis can progress to cirrhosis. Treatment is with steroids and disease-modifying antirheumatic drugs (DMARDs).
A large number of drugs can cause hepatitis. Because the liver plays such a major role in metabolizing drugs, hundreds of medications can cause reactions that are similar to those of acute viral hepatitis. Symptoms can appear anywhere from two weeks to six months after starting drug treatment. In most cases, they disappear when the drug is withdrawn; but, in rare circumstances, they may progress to serious liver disease. Among the drugs most prominently cited for liver interactions are halothane, isoniazid, methyldopa, phenytoin, valproic acid, and the sulfonamide drugs. Notably, very high doses of acetaminophen (Tylenol) have been known to cause severe liver damage and even death, particularly when used with alcohol.
More information on hepatitis
What is hepatitis? - Hepatitis is inflammation of the liver. Hepatitis is characterized by jaundice, enlarged liver, fever, fatigue and abnormal liver function tests.
What causes hepatitis? - Causes of hepatitis including medication side effects, excessive alcohol, some toxic chemicals, disorders of the gall bladder or pancreas, and infections.
Who is at risk of hepatitis? - People who are at risk for developing hepatitis are workers in the health care professions, people with multiple sexual partners, intravenous drug users, and hemophiliacs.
How is hepatitis diagnosed? - Hepatitis is diagnosed during the active illness, based on the symptoms and an examination of the patient. The diagnosis is confirmed by blood samples.
What are the symptoms of hepatitis? - Symptoms of hepatitis vary depending on the cause of the illness. Symptoms of acute viral hepatitis may begin suddenly or develop gradually.
What're the treatment for hepatitis? - No medical treatment is available for acute viral hepatitis. Chronic hepatitis B can be treated with interferon alfa or lamivudine. Chronic hepatitis C can be treated with interferon alfa and ribavirin.
How to prevent hepatitis? - All objects contaminated by blood from patients with hepatitis B or C must be handled with special care. Travelers should be vaccinated against hepatitis A.
What is viral hepatitis? - Viral hepatitis is an infection of the liver that affects people from all walks of life regardless of age, race, gender, or sexual orientation.
What is autoimmune hepatitis? - Autoimmune hepatitis is a chronic inflammatory disease of the liver. Autoimmune hepatitis involves inflammation of the liver caused by rogue immune cells.
What causes autoimmune hepatitis? - The cause of autoimmune hepatitis is unknown. A person with autoimmune hepatitis has autoantibodies circulating in the bloodstream that cause the immune system to attack the liver.
What're the symptoms of autoimmune hepatitis? - Symptoms of autoimmune hepatitis include pain under the right ribs, fatigue and general discomfort, loss of appetite, nausea, sometimes vomiting and jaundice.
How is autoimmune hepatitis diagnosed? - Autoimmune hepatitis can be diagnosed with blood tests, such as liver function tests. Special X-ray tests may be needed.
What's the treatment for autoimmune hepatitis? - Not all patients with autoimmune hepatitis require treatment. Patients are treated with Prednisone including 6 mercaptopurine with or without steroids.
What is alcoholic hepatitis? - Alcoholic hepatitis is a precursor to chronic liver disease and cirrhosis. Alcoholic hepatitis is distinct from cirrhosis caused by long term alcohol consumption.
What causes alcoholic hepatitis? - Alcoholic hepatitis usually occurs after years of excessive drinking. Malnutrition contributes to liver disease.
What are the symptoms of alcoholic hepatitis? - Symptoms of alcoholic hepatitis include abdominal tenderness, spider-like blood vessels in the skin, ascites, poor appetite.
How is alcoholic hepatitis diagnosed? - Diagnostic procedures for alcoholic hepatitis may include specific laboratory blood tests, ultrasound (sonography), and liver biopsy.
What is the treatment for alcoholic hepatitis? - Cessation or marked reduction in alcohol intake is critical in the treatment for alcoholic hepatitis. A multidisciplinary therapy is adopted.
What're complications of alcoholic hepatitis? - Complications of alcoholic hepatitis include variceal bleeding, hepatic encephalopathy, coagulopathy and thrombocytopenia, ascites.
What is hepatitis A? - Hepatitis A is a highly contagious liver infection caused by the hepatitis A virus (HAV). Hepatitis A is primarily spread by fecal-oral transmission.
What causes hepatitis A? - The hepatitis A virus is found in the stools (feces) of people with hepatitis A. Hepatitis A is primarily spread by fecal-oral transmission.
Who is at risk of hepatitis A? - The highest rates of hepatitis A are among children and young adults. Infected people can transmit it to others if they do not take strict sanitary precautions.
What are the symptoms of hepatitis A? - Symptoms of hepatitis A may include fever, nausea, vomiting, jaundice, diarrhea, fatigue, abdominal pain, dark urine and appetite loss.
How is type A hepatitis diagnosed? - The patient will have to have blood tests to confirm the diagnosis of hepatitis A and to see whether your liver has been damaged.
What's the treatment for hepatitis A? - No specific treatment exists for hepatitis A. Initial therapy often consists of bed rest. Gammaglobulin may reduce the severity of the disease.
How to prevent hepatitis A? - Hepatitis A can be prevented by good hygiene and sanitation. Good hygiene in handling food and avoiding contamination of water supplies is important.
Who needs to be vaccinated against hepatitis A? - A vaccine to protect against hepatitis A is available for people who are at high risk of being infected, and for those with existing liver disease.
What is hepatitis B? - Hepatitis B is an inflammation of the liver caused by the hepatitis B virus. The virus that causes hepatitis B is a member of the Hepadnavirus family.
What causes hepatitis B? - Hepatitis B virus is easily spread by direct contact with the blood or body fluids of an infected person. Hepatitis can interfere with normal liver functions.
Who is at the risk of hepatitis B? - Anyone of any age, race, nationality, sex or sexual orientation can be infected with HBV. Sexual activity is an important route for viral transmission of hepatitis B.
What're the symptoms of hepatitis B infection? - Symptoms of hepatitis B infection include nausea (upset stomach), loss of appetite, vomiting, fatigue, and abdominal cramps.
How is hepatitis B diagnosed? - Hepatitis B is diagnosed from the results of specific HBV blood tests (serologies) that reflect the various components of the HBV.
What's the treatment for hepatitis B? - There is no treatment for acute hepatitis B. Treatment of chronic hepatitis B may involve the use of medications such as the antiviral medication.
What's the treatment for chronic hepatitis B? - Treatment of chronic hepatitis B may involve the use of medications such as the antiviral medication alpha interferon.
How to prevent hepatitis B? - Hepatitis B is a preventable disease. Protective practices should be promoted to avoid the risk of transmitting the virus sexually or by contaminated blood.
What about the vaccinations for hepatitis B? - Vaccination against hepatitis B stimulates the body's immune defenses and protects most people. Vaccination reduces the risk for liver cancer.
What is Hepatitis B immune globulin (HBIG)? - Hepatitis B immune globulin (HBIG) is a blood plasma product that can prevent hepatitis B if given within 14 days of an exposure to an infected individual.
What is hepatitis C? - Hepatitis C is a form of hepatitis (liver inflammation). Hepatitis C virus infects the liver and can cause hepatitis.
What causes hepatitis C? - Hepatitis C virus (HCV) is one of the viruses, which together account for the vast majority of cases of viral hepatitis.
Who is at the risk of hepatitis C? - Hepatitis C is spread mainly by direct contact with the blood from an infected person. Other persons at risk include kidney dialysis patients.
What're the complications of hepatitis C? - Hepatitis C exacerbates the severity of underlying liver disease when it coexists with other hepatic conditions.
What're the signs and symptoms of hepatitis C? - Hepatitis C infection has no symptoms and becomes chronic, and can cause cirrhosis and hepatocellular carcinoma.
How is hepatitis C diagnosed? - Hepatitis C infection is usually diagnosed in two steps using blood tests. Diagnostic tests for HCV are used to prevent infection through screening of donor blood and plasma.
What're the treatments for hepatitis C? - The treatment used for hepatitis C most often is a combination of two medicines, pegylated interferon and ribavirin.
How to prevent hepatitis C? - There is no vaccine against HCV. All precautions to prevent infection must be taken including screening and testing of blood and organ donors.
What is hepatitis D? - Hepatitis D or delta virus (HDV) is an infection of the liver caused by a defective virus (delta agent). The delta hepatitis virus (HDV) is an RNA virus.
What causes hepatitis D? - Hepatitis D or delta hepatitis is caused by the hepatitis delta virus (HDV), a defective RNA virus. HDV requires the help of a hepadnavirus.
Who is at risk of hepatitis D? - Individuals who are not infected with HBV, and have not been immunized against HBV, are at risk of infection with HBV with simultaneous or subsequent infection with HDV.
What are the signs or symptoms of hepatitis D? - Symptoms of hepatitis D include nausea, loss of appetite, joint pains, and tiredness, and jaundice.
How is hepatitis D diagnosed? - Hepatitis D infection may be diagnosed by detecting the antibody against the virus and measuring antibodies to delta antigen using ELISA.
What's the treatment for hepatitis D? - There is no effective antiviral therapy available for treatment of acute or chronic type D hepatitis. Liver transplantation has been helpful for treating fulminant acute and end-stage chronic hepatitis.
How to prevent hepatitis D? - Control of HDV infection is achieved by targeting HBV infections. The vaccine against hepatitis B also prevents delta hepatitis.
What is hepatitis E? - Hepatitis E is a contagious virus that causes acute hepatitis. Hepatitis E is also known as epidemic non-A, non-B hepatitis.
What causes hepatitis E? - Hepatitis E is caused by infection with the hepatitis E virus (HEV), a nonenveloped, positive-sense, single-stranded RNA virus.
What're the symptoms of hepatitis E? - Symptoms of hepatitis E include jaundice, anorexia, an enlarged, tender liver, abdominal pain and tenderness, nausea and vomiting.
How is hepatitis E diagnosed? - Diagnosis of hepatitis E is made by blood tests which detect elevated antibody levels of specific antibodies to hepatitis E in the body.
What's the treatment for hepatitis E? - Treatment for hepatitis E is to alleviate symptoms through bed rest, fluid replacement and ensuring there are strategies in place to prevent further transmission.
How to prevent hepatitis E? - The best ways to prevent hepatitis E are to provide safe drinking water and take precautions to use sterilized water and beverages when traveling.