Alcohol is the most commonly used and widely abused psychoactive drug in the country. Ethyl alcohol, or ethanol, is present in varying amounts in beers and wines, and in distilled liquors such as whiskey, gin, and rum. When a person consumes alcohol, the stomach and intestines rapidly absorb it. From there alcohol travels in the blood throughout the entire body, affecting nearly every tissue. Moderate and high doses of alcohol depress the functions of the central nervous system, including the brain. The higher the alcohol level is in the blood, the greater the impairment.

As blood passes through the liver, enzymes break down alcohol into harmless byproducts, which are eliminated from the body six to eight hours later. But the rate at which alcohol accumulates in the body may be faster than the rate at which the body eliminates it, resulting in rising alcohol levels in the blood. Consequently, alcohol remains in the body, producing intoxicating effects hours after the last drink was swallowed.

Small amounts of alcohol may relieve tension or fatigue, increase appetite, or produce an anesthetic affect that numbs pain. Larger quantities inhibit or depress higher thought processes, bolstering self-confidence and reducing inhibition, anxiety, and guilt. As a person becomes intoxicated, painful or embarrassing situations appear less threatening and, as drinking progresses, speech may become loud and slurred. Impaired judgment may lead to incautious behavior, and physical reflexes and muscular coordination may become noticeably affected. If drinking continues, complete loss of physical control follows, ending in stupor, and possibly death.

What are its short-term effects?

When a person drinks alcohol, the alcohol is absorbed by the stomach, enters the bloodstream, and goes to all the tissues. The effects of alcohol are dependent on a variety of factors, including a person's size, weight, age, and sex, as well as the amount of food and alcohol consumed. The disinhibiting effect of alcohol is one of the main reasons it is used in so many social situations. Other effects of moderate alcohol intake include dizziness and talkativeness; the immediate effects of a larger amount of alcohol include slurred speech, disturbed sleep, nausea, and vomiting. Alcohol, even at low doses, significantly impairs the judgment and coordination required to drive a car safely. Low to moderate doses of alcohol can also increase the incidence of a variety of aggressive acts, including domestic violence and child abuse. Hangovers are another possible effect after large amounts of alcohol are consumed; a hangover consists of headache, nausea, thirst, dizziness, and fatigue.

What are its long-term effects?

Prolonged, heavy use of alcohol can lead to addiction (alcoholism). Sudden cessation of long term, extensive alcohol intake is likely to produce withdrawal symptoms, including severe anxiety, tremors, hallucinations and convulsions. Long-term effects of consuming large quantities of alcohol, especially when combined with poor nutrition, can lead to permanent damage to vital organs such as the brain and liver. In addition, mothers who drink alcohol during pregnancy may give birth to infants with fetal alcohol syndrome. These infants may suffer from mental retardation and other irreversible physical abnormalities. In addition, research indicates that children of alcoholic parents are at greater risk than other children of becoming alcoholics.

Health Consequences

While some studies have found that moderate use of alcohol has beneficial health effects, including protection from coronary heart disease, heavy and prolonged intake of alcohol can seriously disturb body chemistry. Heavy drinkers lose their appetite and tend to obtain calories from alcohol rather than from ordinary foods. Alcohol is rich in calories and can provide substantial amounts of energy. However, if it constitutes the primary source of calories in place of food, the body will lack vitamins, minerals, and other essential nutrients.

Prolonged use of large amounts of alcohol may cause serious liver damage. In the first stage of liver disease caused by alcohol, fat accumulates in the liver. This stage of the disease is known as fatty liver. Most people do not notice symptoms of fatty liver, although in some people the liver becomes enlarged and tender. Some people with fatty liver develop hepatitis, which inflames and kills liver cells. Hepatitis is marked by jaundice, which gives a yellowish tint to the eyes and skin. Others may develop cirrhosis, an irreversible condition in which normal liver tissue is replaced by scar tissue. The scarring prevents blood from traveling freely through the liver, building blood pressure in the veins that run from the intestine to the liver. Consequently, the liver can no longer process toxins efficiently, causing poisons to build up in the blood. This buildup can be fatal.

Heavy drinking also damages heart muscle. Nearly half of all cases of cardiomyopathy are caused by alcohol abuse. In this heart disease, the heart muscles, particularly the right and left ventricles, enlarge and become flabby, reducing the heart's blood-pumping efficiency. This inefficiency reduces the flow of blood through the kidneys, which normally filter excess salts and water out of the blood. Eventually the blood volume rises, causing a potentially fatal backup of fluid in the lungs.

Alcoholics tend to have high blood levels of the hormone epinephrine and deficiencies of the mineral magnesium. This combination produces severe arrhythmias, or heartbeat irregularities, a common cause of sudden death in heavy drinkers. Chronic drinkers typically develop hypertension, a leading cause of stroke.

Women who drink excessive amounts of alcohol while pregnant run a high risk of having a baby born with fetal alcohol syndrome (FAS), the leading known cause of birth defects. FAS results in a combination of mental and physical defects, such as retardation, a small head, and poor muscle tone. Some babies exposed to alcohol during fetal maturation develop fetal alcohol effect (FAE), which produce more subtle symptoms, including behavioral problems, difficulty paying attention, or the inability to think abstractly.

Source: National Institutes of Health,
National Institute on Alcohol Abuse and Alcoholism

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