Effects Of Alcohol On The Body

The effects of alcohol on the human body take several forms.

Alcohol, specifically ethanol, is a potent drug with a range of side effects. The amount and circumstances of consumption play a large part in determining the extent of intoxication, e.g. consuming alcohol after a heavy meal is less likely to produce visible signs of intoxication than consumption on an empty stomach. Hydration also plays a role, especially in determining the extent of hangovers.

Alcohol has a biphasic effect on the body, which is to say that its effects change over time. Initially, alcohol generally produces feelings of relaxation and cheerfulness, but further consumption can lead to blurred vision and coordination problems. Cell membranes are highly permeable to alcohol, so once alcohol is in the bloodstream it can diffuse into nearly every tissue of the body. After excessive drinking, unconsciousness can occur and extreme levels of consumption (when the concentration of alcohol in the bloodstream is over 0.5 %) can lead to alcohol poisoning and death. Death can also be caused by asphyxiation if vomit, a frequent result of overconsumption, blocks the trachea and the individual is too inebriated to respond. An appropriate first aid response to an unconscious, drunken person is to place them in the recovery position.

Intoxication frequently leads to a lowering of one's inhibitions, and intoxicated people will do things they would not do while sober, often ignoring social, moral, and legal considerations. The term intoxication is typically used in legal proceedings when some crime has been committed during a state of inebriation.



Intoxication. In small amounts, ethanol causes a mild euphoria and removes inhibitions. In large doses, ethanol acts as a central nervous system depressant and causes drunkenness, generally at a blood ethanol content of about 0.1%. At higher contents, alcohol causes intoxication, coma and death. A blood ethanol content above 0.4% can be fatal, although regular heavy drinkers can tolerate somewhat higher levels than non-drinkers. Eight to ten drinks per hour is considered a fatal dosage for the average 54 kg (119 lb.) person. One drink is equivalent to one shot of 40% abv (80 proof) liquor, one 12 US fl oz (355 ml) beer, or one 4–5 US fl oz (120–150 ml) glass of wine.

Thus a "shot" of 40% ABV liquor in the US (which is ~44ml or 1.5 US fl oz) is actually 1.76 units of alcohol. ((40*44)/1000) Unfortunately, in the US, most still have the misconception that one US shot is 1 unit when in fact it is almost double that; which can lead to health problems and more drunken driving.

The highest recorded non-lethal level of blood alcohol is 0.914 mg/dl.

Alcoholism, the dependency on alcohol, is a major public health problem. Alcoholics develop a number of health problems, with cirrhosis of the liver among the most significant. Unlike withdrawal from other drug/intoxicants, withdrawal from heavy alcohol consumption can be fatal and is known as delirium tremens.

Excessive alcohol consumption during pregnancy carries a heavy risk of causing a series of permanent mental and physical defects in the child, known as fetal alcohol syndrome.



Action on the Brain. Ethanol is quickly absorbed into the bloodstream and reaches the brain. As a small molecule, it is able to cross the blood-brain barrier. For reasons that are still being studied, it then triggers the release of dopamine and endorphins into the bloodstream, which cause euphoria.

Alcohol Effects by Dose. The effects of alcohol on the body is as follows (BAC = Blood Alcohol Content):

Euphoria (BAC = 0.03 to 0.12 %) Subject may become more self-confident or daring. Their attention span shortens. They may look flushed. Their judgement is not as good -- they may express the first thought that comes to mind, rather than an appropriate comment for the given situation. They have trouble with fine movements, such as writing or signing their name.

Excitement (BAC = 0.09 to 0.25 %) Subject may become sleepy. They have trouble understanding or remembering things (even recent events). They do not react to situations as quickly (if they spill a drink they may just stare at it). Their body movements are uncoordinated. They begin to lose their balance easily. Their vision becomes blurry. They may have trouble sensing things (hearing, tasting, feeling, etc.).



Confusion (BAC = 0.18 to 0.30 %) Profound confusion -- uncertain where they are or what they are doing. Dizziness and staggering occur. Heightened emotional state -- aggressive, withdrawn or overly affectionate. Vision, speech and awareness are impaired. Poor coordination, and pain response. Nausea and vomiting often occur.

Stupor (BAC = 0.25 to 0.4 %) Movement severely impaired. Lapses in and out of consciousness occur, and subjects can slip into a coma ; will become completely unaware of surroundings, time passage, and actions. Risk of death is very high due to alcohol poisoning and or inhalation of vomit while unconscious.

Coma (BAC = 0.35 to 0.50 %) Unconsciousness sets in. Reflexes are depressed (i.e. pupils do not respond appropriately to changes in light). Breathing is slower and more shallow. Heart rate drops, and death usually occurs at levels in this range.

Death (BAC more than 0.50 %) - Alcohol causes Central Nervous System to fail resulting in death.





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