Moreover, the excessive and chronic alcohol is the single most important cause of illness and death from hepatitis and cirrhosis in the United States.

Normal Liver:
Normal functioning of the liver is essential to life. The liver is the largest and, in some ways the most complex organ in the body. One of its main functions is to degrade toxic substances absorbed from the intestine or produced in other areas of the body and then excretes them through the bile or blood products as harmless.

Moreover, the liver secretes bile into the small intestine to help digestion and absorption of fats, vitamin stores, synthesizes proteins and cholesterol, metabolizes and stores sugars. The liver controls blood viscosity and regulates the clotting mechanisms.

Alcoholic liver disease:
The liver is an organ particularly susceptible to damage caused by alcohol, since it is the major site of metabolism of this substance in the body.

In the liver is one of the largest organs of the human body, it has the ability to regenerate, therefore, symptoms related to liver damage caused by alcohol may not appear until it is really extensive. In males, this condition can be achieved by using about 2 liters of beer, 1 liter of wine or 240 ml of distilled beverages ingested daily for at least 20 years. In women, the amount needed to produce similar injuries is only ¼ to ½ of this amount.

Daily consumption of alcohol over a long period of time, is a condition strongly associated with the development of liver injury, however, only half of the users who use it with this frequency will develop hepatitis or alcoholic cirrhosis. These findings suggest that other conditions such as heredity, environmental factors or both should influence the course of liver disease.

Alcohol metabolism:
Most of the ingested alcohol is metabolized in the liver by action of the enzyme alcohol dehydrogenize (ADH). This enzyme converts the alcohol into acetaldehyde, which even in small concentrations, is toxic to the body. The enzyme aldehyde dehydrogenize (ALDH), in turn, converts the acetaldehyde into acetate 3. Most of the acetate produced reaches other parts of the body through the bloodstream where it participates in other metabolic cycles.

In individuals who abuse alcohol liver disease most commonly found is:
1. Alcoholic (fatty liver). Fat deposition occurs in almost all individuals who abuse alcohol and frequent. However, it is a clinical condition that can also occur in nonalcoholic individuals after a single episode of alcohol abuse. It is the first stage of alcoholic liver disease. If the person stops drinking at this stage, it will recover its function. It may also occur in diabetic, obese, with severe malnutrition and users of certain drugs 3.

2. Alcoholic Hepatitis: This condition results in inflammation and / or destruction of liver tissue. Symptoms include loss of appetite, nausea, vomiting, abdominal pain, fever and in some cases, confusion. Although this disease can lead to death, in most cases it can be reversed with abstinence from alcohol.
3. Cirrhosis: It is an advanced form of liver disease caused by a progressive damage of liver cells. Cirrhosis is usually diagnosed in 15 to 30% of chronic users of alcohol and abusive.

A cirrhotic liver is characterized by an extensive fibrosis that affects the functioning of the liver could affect the functioning of other organs such as brain and kidneys. Although alcoholic cirrhosis can lead to death due to complications, it can be stabilized by complete abstinence from alcohol.

The intense and chronic consumption of alcohol predisposes to liver disease in susceptible individuals. However, the fact that only a proportion of these individuals develop hepatitis or cirrhosis, indicating the importance of other factors such as heredity, gender, diet and other forms of liver diseases influencing the risk for alcoholic liver disease.

Most liver injuries caused by alcohol are attributed to alcohol metabolism and its products of metabolism. Other research will bring other possible biological mechanisms involved in liver damage, and treatment alternatives as depended or not alcohol.