Hepatitis is an inflammation of the liver. In chronic hepatitis, liver inflammation continues for at least six months. This condition may be mild, causing relatively little damage, or more serious, causing many liver cells to be destroyed. Some cases lead to cirrhosis and liver failure.
Viruses are the most common cause of chronic hepatitis. Viruses that cause hepatitis include:
Hepatitis B and C. These viruses cause two-thirds of all cases of chronic hepatitis. People infected with hepatitis C have the greatest risk of developing chronic hepatitis. Both of these viruses usually begin with mild symptoms. Over time, perhaps a decade or more, both may lead to the serious complication of cirrhosis due to ongoing destruction of liver cells and resultant scarring. A minority of patients with cirrhosis develop liver cancer over time.
Hepatitis D. Hepatitis D infects only patients already infected with hepatitis B, and it generally results in a flare of active hepatitis.
The three more commonly diagnosed causes of non-infectious chronic hepatitis include:
Alcohol. Alcohol can cause a chronic hepatitis, especially if associated with inadequate nutrition. Also, even moderate intake of alcohol can make chronic hepatitis from any other cause (especially hepatitis C) worse, with an increased risk of advancing to cirrhosis.
Non-alcoholic steatohepatitis (NASH). Nonalcoholic steatohepatitis or NASH has become a relatively common cause of persistent liver inflammation. "Steato" means fat and the hallmark of NASH is fat in the liver AND active on-going liver damage. Most people have no symptoms. They are usually discovered when a routine blood test is performed and the level of liver enzymes are found to be above normal.
Autoimmune hepatitis. In this form of chronic hepatitis, the immune system mistakenly destroys the body's own liver cells. What triggers autoimmune chronic hepatitis is unknown. If left untreated, it's a progressive disease that can lead to cirrhosis. It may appear with other autoimmune diseases, such as Sjogren's syndrome and autoimmune hemolytic anemia. Autoimmune hepatitis most often is found in young women, but it can affect women and men of all ages.
Some medications also can lead to chronic hepatitis. These medications include:
Isoniazid (Laniazid, Nydrazid) for tuberculosis
Methyldopa (Aldomet, Amodopa) for high blood pressure (hypertension)
Phenytoin (Dilantin) for seizure disorders
Macrodantin for urinary tract infections
However, chronic hepatitis caused by medications is relatively uncommon. Periodic blood tests are warranted when patients are placed on drugs known to cause hepatitis. Discontinuing the medication usually reverses early liver inflammation.
Some rare, inherited metabolic disorders also can lead to chronic hepatitis. They include:
Wilson's disease, a condition in which the body has difficulty metabolizing copper
Hemochromatosis, a condition of excessive iron deposits in the liver and many other parts of the body