What Causes Hangovers?

Published On: June 23, 2015

A close friend recently told me didn’t like to drink an ‘excessive’ amount of alcohol now he’s in his thirties. I ask him why this was so. He claims hangovers are now too painful to bear now he’s thirty-three. He claims his hangovers have gotten progressively worse as he has gotten older.

Well, he’s not alone. This is because many of us blame the severity of our hangover on our age.

But is this true?

The aim of this blog post is to unravel causes of the humble hangover, including the effect of age.

The liver and the hangover

One theory offered by scientists as to the cause of hangovers involves the liver. So the theory goes: alcohol is absorbed into the blood via the stomach and small intestine. Alcohol is then transferred to the liver. An enzyme in the liver known as ADH converts alcohol into a far more toxic substance known as ‘acetaldehyde’. Scientists estimate acetaldehyde is thirty times more toxic than alcohol. Over time another enzyme known as ALDH converts acetaldehyde into acetate. Acetate is then broken down into carbon dioxide and water.

Scientists believe many hangover-type symptoms are a result of high acetaldehyde levels in the blood. It takes the liver one hour to process one unit. The more you drink the longer it takes the liver to neutralise toxic acetaldehyde. Thus acetaldehyde is given enough time to cause damage to cells in the body. This damage is thought to contribute to hangover symptoms.

The digestion system and the hangover

Another theory attempting to explain why we experience a hangover involves the digestive system. Alcohol is absorbed through the stomach, small intestine and large intestine’s walls. This causes the stomach to produce more hydrochloric acid. In turn, this leads to inflammation. A US study claims this inflammation of the gut allows endotoxins into the blood. This is known as ‘leaky gut syndrome’ or ‘gastritis’. Endotoxins are toxins released by bacteria when they die. In turn, the body fights these toxins through an immune response. This is to fight off a condition known as ‘endotoxemia’. Endotoxemia is believed to cause alcoholic hepatitis. Scientists claim this immune response is responsible for hangover type symptoms such as nausea, fever and muscle pain.

Genetics and the hangover

An Australian study conducted on four thousand twins illustrates the link between a hangover and genetics. Factors included the amount of alcohol one is likely to drink and the speed in which acetaldehyde is converted into harmless by-products such as carbon dioxide and water. These factors are largely determined by genetics.

Race and the hangover

A mutated gene is commonly found in the liver of East Asian people. This gene increases the rate at which acetaldehyde is produced from alcohol. Acetaldehyde is thirty times more toxic to the body than alcohol. Thus those affected by this gene mutation suffer hangover-type symptoms more-so than people who are not affected by this mutation. Symptoms generally include nausea and flushing.

Age and the hangover

The link between a hangover and the sufferer’s age is well established. Tests carried out on rats illustrated this link. Adolescent rats suffer fewer hangover-type symptoms than did adult rats. One reason for this is because our livers become less efficient at converting harmful acetaldehyde into water and carbon dioxide as we get older.

As we get older we tend to gain body fat. A greater body fat index leads to a greater ‘blood alcohol content’ when we get drunk. A higher percentage of body fat is the chief reason women get drunk much quicker than do men.

Drink type and the hangover

Another factor influencing the severity of a hangover is the type of drink you consume. Scientists believe dark drinks (e.g. red wine, brandy and whisky) contain more ‘congeners’ than their whiter counterparts (e.g. white wine, gin and vodka). Congeners are fermented by-products produced during brewing. The body converts congeners into toxins known as ‘formaldehyde’. Scientists believe this toxin causes hangover style symptoms.

Carbonated alcoholic drinks are also thought to increase the symptoms of a hangover. For instance, Champagne contains lots of carbon dioxide. This increases the absorption of alcohol through the stomach and gut walls. Beer is also highly carbonated. If you drink beer and then drink spirits, scientists believe beer’s fizz increases the rate in which the spirit is absorbed into the bloodstream.


I hope you enjoyed this post on hangovers. It seems age does affect the severity of one’s hangover. But age is not the only factor at play. Remember to drink in moderation. If you or a loved one suffers from alcoholism, be sure to contact Rehab 4 Alcoholism. With private alcohol rehab centres throughout the United Kingdom, I am sure our advisors will find a suitable centre near you.

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