Alcohol in the Body

  1. Alcohol in the Gastrointestinal System
  2. Alcohol in the Liver
  3. Alcohol in the Brain
  4. Fetal Alcohol Syndrome
  5. Blackouts
  6. Alcohol & Exercise
  7. Hangovers
  8. Dehydration
  9. Alcohol & Sleep
  10. Alcohol & Violence
  11. Alcohol & Medication
  12. Alcohol & Drugs
  13. Alcohol & Skin
  14. Other Harms

Alcohol in the Gastrointestinal System

Everyone has an enzyme in their stomach which processes ethanol into a safer substance. The enzyme is called alcohol dehydrogenase. Heavy drinkers and people with alcohol problems have severely reduced levels of this important enzyme

When a person drinks alcohol, about 20% of the alcohol is absorbed in the stomach and 80% is absorbed in the small intestine.

The longer the stomach has to work on the ethanol, two effects may occur… enzymes will work on some of it, and the speed at which the body absorbs it will be slowed.  When a meal is eaten the exit valve of the stomach closes in order to digest the food. When food and alcohol are consumed at the same time this prevents the alcohol from passing quickly into the small intestine from where it would be rapidly absorbed giving dehydrogenase more time to work.

In general, the less you weigh the more you will be affected by a given amount of alcohol. But alcohol has a high affinity for water so an individual who is well muscled will be less affected than someone with a higher percentage of fat since fatty tissue does not contain water and will thus not absorb as much alcohol

Alcohol is a strong poison.  As such, when it enters the body, many organs go to work to expel it from the body as quickly as possible. Once absorbed by the stomach or small intestine, alcohol circulates in the bloodstream until it is processed by to the liver or lost through the urine, breath, or skin. The Liver is the main organ that rids the body of alcohol by breaking it down. It metabolizes about 90% of the alcohol in our body while about 10% is processed by the kidneys, lungs, and skin, and thereby excreted through either our urine or breath, or skin surface.

Alcohol in the Liver

The liver is where the body finishes breaking down alcohol.

If you drink alcohol faster than your liver can process alcohol, you will begin to notice its affects.

The Liver is the main organ that rids the body of alcohol by breaking it down. It metabolises about 90% of the alcohol in our body while about 10% is excreted through either our urine or breath.

The liver also produces more toxins in the body as a by-product of breaking down alcohol. When the liver is metabolising alcohol it produces acetaldehyde, a substance which has toxic effects on our liver, brain and stomach lining, resulting in headache, nausea, vomiting and heartburn (aka hangover).

Alcohol in the Brain

While in the blood stream, alcohol instantly travels to all organs of the body, including the brain. In the brain alcohol can impair our faculties, creating difficulty walking, blurred vision, slurred speech, slowed reaction times, very poor judgment, and memory impairment. These impairments can begin to happen after only a small amount of alcohol, perhaps after only one or two drinks, at BAC levels as low as .02 depending on the individual.

In social drinkers impairment disappears as one sobers up. In chronic drinkers these symptoms can become long term.

Alcohol effects on the brain Factors influencing the degree to which the brain is affected by drinking include:

At relatively low levels (less than .07 BAC) alcohol stimulates electrical activity in the brain affecting pleasure and euphoria. It also works on the circuits targeted by drugs like Valium - calming, easing anxiety, and acting as a relaxant. Alcohol also acts on the serotonin system, which like Prozac can increase self-confidence and reduce depression.

In larger quantities (over .08 BAC) alcohol interferes with chemical messages in the brain. It can make you clumsy, affect your coordination and slur your speech. It dramatically reduces your ability to learn and form memories. Regular drinking sessions can make it very difficult to learn new skills or retain new knowledge.

After many years of heavy drinking adults with alcoholism show smaller brain sizes and run the risk of developing serious and permanent changes in the brain. Wernicke–Korsakoff Syndrome is a degenerative brain disorder usually found in poorly nurished chronic alcoholics. It results in severe mental confusion, paralysis of the nerves that move the eyes and difficulty with muscle coordination. Sufferers may be too confused to find their way out of a room or may not even be able to walk. This chronic and debilitating syndrome is also characterized by persistent learning and memory problems. Victims are forgetful, quickly frustrated, and have long term memory recall problems as well as difficulty with new memory formation.

Fetal Alcohol Syndrome (FAS)

Drinking during pregnancy can lead to a range of physical, learning, and behavioral effects in the developing brain, the most serious of which is a collection of symptoms known as fetal alcohol syndrome (FAS).

As compared to healthy babies, babies born with FAS have:

Never drink during pregnancy.


Blackouts are among the most dangerous of all alcohol related effects. Imagine being conscious but having little or no control over your actions. Imagine having no ability to judge the riskiness and danger of your behavior or its impact on others. Worse yet, you have no recall of what you did during this time.

Alcohol is well known to interfere with the hippocanthus, the part of the brain responsible for memory formation. Heavy drinking hinders the development of new long-term memories and frequently causes fragmentary or total memory loss of events during periods of rapid drinking (binge drinking). We call these "blackouts" though "episodic amnesia" might be a more clinical description. Blackouts can last anywhere from several minutes to several hours.

These episodes are not to be confused with "passing out", where the subject looses consciousness. In a blackout, it is only the memory of events during the period of alcohol intoxication that are lost. Memory loss can include everything up to and including acts of violence, vandalism, sexual intercourse and driving.

Blackouts can affect alcoholics, heavy drinkers as well as social and college drinkers. Blackouts occur with greater frequency over .25 BAC, over three times the legal drinking limit. Predictors of blackout also include rapid drinking or guzzling of hard liquor. The more rapidly one drinks the higher the likelihood of blacking out.

In a survey of 772 undergraduates (Wechsler et al. 2002), 40% of the students who had consumed alcohol reported experiencing at least one blackout in the preceding twelve months. 9.4% of these drinkers who reported drinking in the previous two weeks also reported having blackouts as a result.

The best way to reduce the danger of blackouts is avoid binge drinking. Don’t drink on an empty stomach and don’t drink at rates faster than your body can metabolize the alcohol.

Further Information:

Alcohol & Exercise

Alcohol affects the body's ability to turn food into energy; it slows down reaction times, increases body heat loss and reduces endurance. If you have alcohol 24 hours before exercising you are more likely to develop muscle cramps. After exercising the body needs to be re-hydrated. And drinking alcohol after exercise will just dehydrate the body further.

It is also important to remember that drinking before or during exercise can lead to injuries. Alcohol impacts injuries such as bruising or bleeding as it slows down the ability of blood to clot.


Hangover symptoms include headache, feeling sick or depressed, general grouchiness and diarrhea.

Hungover from alcohol intoxication Aside from the alcohol, drinks have small amounts of additives (congeners) that give drinks their color, flavor and smell. Congeners affect everyone differently and may contribute to you feeling ill.

The pounding headache is caused by dehydration. Alcohol's toxicity can cause acids to accumulate in the stomach and intestines resulting in queasiness and nausea. The stomach lining becomes inflamed (gastritis) delaying digestion.

Alcohol can inflame the esophagus, the tube that carries food from the throat to the stomach, giving you heartburn.

When you drink, you take in large quantities of increased glucose. The Pancreas responds to this by producing more insulin, which removes the glucose. Once the process has started, the insulin carries on working removing glucose from the blood. Low blood glucose levels are responsible for the shakes, excess sweating, dizziness, blurred vision and tiredness.

Alcohol often affects bowel movements, in the normal course, the small and large intestines reabsorb salt and water, but alcohol interferes with this process often causing diarrhea.

The only true cure for a hangover is time, however there are some things you can do to lessen your discomfort. Drink plenty of water, nourish your body with food, toast and fruit at breakfast. Consume food with some sugar since alcohol has broken down the liver's sugar stores. Get plenty of rest and sleep.


Alcohol is diuretic. It promotes water loss through frequent urination leading to dehydration.

Alcohol also attacks our stores of vitamins and minerals, which need to be in the correct balance for the body to function normally. Dehydration caused by drinking can affect the balance by draining potassium from the body, resulting in thirst, muscle cramps, dizziness and faintness.

Alcohol & Sleep

Alcohol interferes with sleeping rhythms, while dehydration reduces the rest we get. Alcohol also relaxes muscles in the back of the mouth, increasing the likelihood of snoring.

Alcohol & Violence

Alcohol lowers people's inhibitions and often means that aggressive people become more aggressive when drunk.

Because it lowers inhibitions and affects judgement, alcohol can also trigger violent and confrontational behaviour in normally quiet people. It is also true that people who have consumed alcohol are more likely to become victims of violence and sexual assault.

Alcohol & Medication

It can be dangerous if you are taking prescription, or over the counter medications. Medication that slows you down or sedates you can be very dangerous when combined with alcohol. You might find you have difficulty breathing and a great deal of difficulty thinking clearly.

You need to be careful with the following drugs: Avoid mixing Alcohol and Medication

Ask your doctor or pharmacist what could happen if you are prescribed medication and you want to drink.

Alcohol & Drugs

Drinking alcohol and taking other drugs like tranquillizers (valium), amphetamines (speed), antidepressants (prozac) or marijuana (cannabis, pot or weed) increase the effects of all the drugs in your body. This is dangerous and potentially fatal because you have no idea how you might react to this mix.

Alcohol & Skin

Alcohol dehydrates your body and your skin, also causing redness of the skin or makes it appear blotchy. It can permanently enlarge the peripheral vessels of the skin, thus causing the enlarged red nose sometimes associated with heavy drinkers. It is common for drinkers to report a warming sensation of the skin.

Other Harms

When you gamble with alcohol, it's not only yourself that you are putting at risk: