While light-to-moderate drinking is associated with some benefits, excessive use of alcohol has well-established adverse effects on health and well being. As with many substances, toxicity depends upon the dose. In the United States, moderate drinking is defined as no more than two drinks per day for men, and one drink per day for women. Beyond the point of moderate drinking, risks due to the direct toxic effects of alcohol begin to rise.
Immediate Health Risks
Drinking too much plays a role in many risky behaviors that have quick and direct harmful health effects. The Centers for Disease Control describes accidents and injuries, violence, risky sexual conduct and alcohol poisoning as some of the more immediate deleterious effects of alcohol abuse. Binge drinking is of particular concern with regard to accidents and high-risk behaviors.
Liver Disease
Alcoholic hepatitis, an inflammation of the liver, and cirrhosis are potential adverse outcomes of alcohol abuse. Alcoholic cirrhosis is a condition whereby the normal structure of the liver is replaced with scar tissue. The American Liver Foundation says that cirrhosis occurs in an estimated 10 to 20 percent of heavy drinkers after a period of 10 years of alcohol abuse. Increased risk of liver cancer is another effect of chronic, heavy drinking.
Cardiovascular Disease
Heavy, long-term drinking can lead to an enlarged heart and to heart rhythm problems, according to the Merck Manuals Medical Library. Heavy or binge drinking can lead to high blood pressure and stroke.
Cancer
Regular alcohol consumption is correlated with oral, throat, esophageal, liver and breast cancers. The American Cancer Association reports that about 80 percent of men with oral cancers frequently drink alcohol. Additionally, a study published in the February 24, 2009 issue of the "Journal of the National Cancer Institute," concluded that consuming 3 or fewer drinks per day raised the risk of developing some cancers. The study involved over 1 million women in the United Kingdom and found an increased incidence of oral cavity, throat, esophagus, liver, rectal and breast cancers.
Pancreatic Disease
An inflamed pancreas is a serious health problem that can lead to long-term damage of this organ. Heavy, chronic alcohol abuse increases the risk for either acute or chronic pancreatitis.
Neurological Disease
The National Institute on Alcohol Abuse and Alcoholism describes the damaging effects of long-term alcohol abuse on the brain, ranging from memory lapses and blackouts to the brain disorder known as Wernicke--Korsakoff syndrome.This disorder is related to an alcohol-induced thiamine deficiency and can result in confusion, lack of coordination and paralysis of the nerves of the eye muscles.
