A colourless liquid, also called ethanol or ethyl-alcohol, produced by the fermentation of carbohydrates by yeast. Medically, alcohol is used as a solvent and an antiseptic; recreationally it is a widely used drug, taken in alcoholic drinks to give a pleasant taste as well as to relax, reduce inhibitions, and increase sociability. Taken to excess, alcohol causes much mental and physical harm – not just to the individual imbibing it, but often to their family, friends, community and work colleagues.
Alcohol depresses the central nervous system and disturbs both mental and physical functioning. Even small doses of alcohol will slow a person’s re?exes and concentration; potentially dangerous effects when, for example, driving or operating machinery. Drunkenness causes slurred speech, muddled thinking, amnesia (memory loss), drowsiness, erectile IMPOTENCE, poor coordination and dulled reactions – thereby making driving or operating machinery especially dangerous. Disinhibition may lead to extreme euphoria, irritability, misery or aggression, depending on the underlying mood at the start of drinking. Severe intoxication may lead to COMA and respiratory failure.
Persistent alcohol misuse leads to physical, mental, social and occupational problems, as well as to a risk of DEPENDENCE (see also ALCOHOL DEPENDENCE). Misuse may follow several patterns: regular but controlled heavy intake, ‘binge’ drinking, and dependence (alcoholism). The ?rst pattern usually leads to mainly physical problems such as gastritis, peptic ulcer, liver disease, heart disease and impotence. The second is most common among young men and usually leads to mainly social and occupational problems – getting into ?ghts, jeopardising personal relationships, overspending on alcohol at weekends, and missing days o? work because of hangovers. The third pattern – alcohol dependence – is the most serious, and can severely disrupt health and social stability.
Many researchers consider alcohol dependence to be an illness that runs in families, with a genetic component which is probably passed on as a vulnerable personality. But it is hard to disentangle genetic, environmental and social factors in such families. In the UK there are estimated to be around a million people suffering from alcohol dependence and a similar number who have di?culty controlling their consumption (together about 1:30 of the population).
Alcohol causes tolerance and both physical and psychological dependence (see DEPENDENCE for de?nitions). Dependent drinkers classically drink early in the morning to relieve overnight withdrawal symptoms. These symptoms include anxiety, restlessness, nausea and vomiting, and tremor. Sudden withdrawal from regular heavy drinking can lead to life-threatening delirium tremens (DTs), with severe tremor, hallucinations (often visual – seeing spiders and monsters, rather than the pink elephants of romantic myth), and CONVULSIONS. This must be treated urgently with sedative drugs, preferably by intravenous drip. Similar symptoms, plus severe INCOORDINATION and double-vision, can occur in WERNICKE’S ENCEPHALOPATHY, a serious neurological condition due to lack of the B vitamin thiamine (whose absorption from the stomach is markedly reduced by alcohol). If not treated urgently with injections of thiamine and other vitamins, this can lead to an irreversible form of brain damage called Korsako?’s psychosis, with severe amnesia. Finally, prolonged alcohol misuse can cause a form of dementia.
In addition to these severe neurological disorders, the wide range of life-threatening problems caused by heavy drinking includes HEPATITIS, liver CIRRHOSIS, pancreatitis (see PANCREAS, DISEASES OF), gastrointestinal haemorrhage, suicide and FETAL ALCOHOL SYNDROME; pregnant women should not drink alcohol as this syndrome may occur with more than a glass of wine or half-pint of beer a day. The social effects of alcohol misuse – such as marital breakdown, family violence and severe debt – can be equally devastating.
Treatment of alcohol-related problems is only moderately successful. First, many of the physical problems are treated in the short term by doctors who fail to spot, or never ask about, heavy drinking. Second, attempts at treating alcohol dependence by detoxi?cation or ‘drying out’ (substituting a tranquillising drug for alcohol and withdrawing it gradually over about a week) are not always followed-up by adequate support at home, so that drinking starts again. Home support by community alcohol teams comprising doctors, nurses, social workers and, when appropriate, probation o?cers is a recent development that may have better results. Many drinkers ?nd the voluntary organisation Alcoholics Anonymous (AA) and its related groups for relatives (Al-Anon) and teenagers (Alateen) helpful because total abstinence from alcohol is encouraged by intensive psychological and social support from fellow ex-drinkers.
Useful contacts are: Alcoholics Anonymous; Al-Anon Family Groups UK and Eire (including Alateen); Alcohol Concern; Alcohol Focus Scotland; and Alcohol and Substance Misuse.
1 standard drink =1 unit
=••• pint of beer
=1 measure of spirits
=1 glass of sherry or vermouth
=1 glass of wine
Limits within which alcohol is believed not to cause long-term health risks:
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