What are the causes for Alcoholic hepatitis?

Alcoholic hepatitis occurs when the liver is damaged by the alcohol you drink. Just how alcohol damages the liver -— and why it does so only in a minority of heavy drinkers — isn't clear. What is known is that the process of breaking down ethanol — the alcohol in beer, wine and liquor — produces highly toxic chemicals, such as acetaldehyde. These chemicals trigger inflammation that destroys liver cells. Over time, web-like scars and small knots of tissue replace healthy liver tissue, interfering with the liver's ability to function. This irreversible scarring, called cirrhosis, is the final stage of alcoholic liver disease.

Risk increases with time, amount consumed

Heavy alcohol use can lead to liver disease, and the risk increases with the length of time and amount of alcohol you drink. But because many people who drink heavily or binge drink never develop alcoholic hepatitis or cirrhosis, it's likely that factors other than alcohol play a role. These include:

  • Other types of hepatitis. Long-term alcohol abuse worsens the liver damage caused by other types of hepatitis, especially hepatitis C. If you have hepatitis C and also drink — even moderately — you're more likely to develop cirrhosis than if you don't drink.
  • Malnutrition. Many people who drink heavily are malnourished, either because they eat poorly or because alcohol and its toxic byproducts prevent the body from properly absorbing and breaking down nutrients, especially protein, certain vitamins and fats. In both cases, the lack of nutrients contributes to liver cell damage.
  • Obesity.
  • Genetic factors. Having mutations in certain genes that affect alcohol metabolism may increase your risk of alcoholic liver disease as well as of alcohol-associated cancers and other complications of heavy drinking. The exact genetic associations have not yet been identified.

Source: http://www.mayoclinic.com