What makes you feel drunk?

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

One of the most rapid affects of alcohol is on the central nervous system (CNS), which controls a range of vital body functions including speech, muscles, sense organs and sweat glands.

Usually the CNS receives information from organs such as the eyes and ears, analyses it and then responds, perhaps by contracting a muscle. However, alcohol impairs our CNS functioning which, in turn, causes the usual symptoms of being drunk. These include disturbed balance, slurred speech, blurred vision, excess sweating and the dulling of our sensation of pain.

Alcohol also affects the outer layer of the brain (the frontal cortex) that is concerned with conscious thought. This is why people under the influence of alcohol often lose their inhibitions and dance on the tables.

Learning how alcohol affects your body can help you control your drinking and enjoy your night out more.

What makes you feel so lousy?

Dehydration: Alcohol is a diuretic. This means it encourages the body to lose more water than it takes on by halting the production of the body's anti-diuretic hormone. This means you feel the need to pee excessively, thus speeding up the loss of fluid from the body that leads 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.

The shakes: When a person drinks, they take in large quantities of increased glucose. Their body 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.

Munchies: To overcome this feeling of lethargy the body craves a carbohydrate boost, which is why many people want chips when they have been drinking.

Breaking it down

The liver is the main organ that gets rid of alcohol by breaking it down. It metabolises about 90% of the alcohol in our body while only about 10% is excreted through either our urine or breath. The liver metabolises alcohol at the rate of one to two units per hour, sometimes less than that in women.

The liver needs water to get rid of toxins from the body but, as alcohol acts as a diuretic, there will not be sufficient amounts in the body, so the liver is forced to divert water from other organs including the brain, which causes the throbbing headaches.

The liver also produces more toxins in the body as a by-product during the breakdown of 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 severe headache, nausea, vomiting and heartburn (aka hangover).

Sleep

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

The Morning after

If your alcohol consumption was fairly high the night before, then you will be greeted with more than a common hangover the next day. You could have one or all of these:

• The toxicity of alcohol can irritate the stomach causing gastritis (chronic stomach upset) often leading to vomiting.
• Alcohol can cause inflammation of the oesophagus, the tube that carries food from the throat to the stomach, causing heartburn.
• Alcohol often affects your bowel movements. The small and large intestine reabsorb salt and water but alcohol interferes with this process often causing diarrhoea.

Updated: 24/02/2012