Why Do I Get a Headache After Drinking a Small Amount of Alcohol?

If you've ever found yourself waking up with a splitting headache and foggy memories after a night of drinking, you're not alone. Plenty of people experience unpleasant headaches as a result of alcohol consumption. Even a single drink can be enough to trigger head pain, nausea, and dizziness in some unlucky folks.

The causes vary from person-to-person, but common culprits include dehydration from the diuretic effects of alcohol, natural sensitivities to ingredients, or a reaction related to temporary spikes in blood pressure and dilation of blood vessels. Genetics and ethnical background also seem to play a role in determining who suffers hangover headaches and how severely.

If you dread the morning migraine almost as much as the embarrassing drunk dial, read on to uncover why it happens and - more importantly - what you can do prevent it. This article will explore the science behind the dreaded hangover headache, risk factors to be aware of, and lifestyle changes and coping strategies you can try.

Headaches Can Happen After Small Amounts of Alcohol

There are 3 main headache types that can occur from drinking even tiny amounts of alcohol. These include migraines, cluster headaches, and tension headaches.

Migraine Headaches

For people prone to migraines, even the smallest amount of alcohol can be enough to ruin a fun night out.

In fact, a 2008 study found that about one-third of migraine sufferers listed alcohol as an occasional migraine trigger, whilst about 10% of sufferers said it triggered their migraines frequently.

It is not fully understood why this is, but some studies point to the toxic effects of chemicals in alcoholic beverages, like congeners, as a possible culprit.

Drinks that often contain congeners include:

• Bourbon
• Whiskey
• Red wine
• Brandy

A more recent 2019 study also highlighted histamines as a culprit for migraines. Alcohol not only contains histamines, it can also cause your body to create them.

This is common in people with Asian flush who have trouble breaking down a toxic alcoholic metabolite called acetaldehyde.  Not being able to breakdown this toxin causes the body to produce more histamines. This can trigger migraines after drinking only a small amount of alcohol.

In addition to the above two points, alcohol can also cause dehydration. According to an article from the American Migraine Foundation, about one-third of migraine sufferers say dehydration is a common trigger, and for some, even the slightest hint of dehydration can cause unbearable head pain.

Cluster Headaches

Cluster headaches are a very severe form of headache that happens in cycles, usually followed by headache-free periods.

Even the smallest amount of alcohol can trigger a cluster headache attack for people prone to these kinds of headaches. They usually occur within about 2 hours of drinking alcohol - though some reliably report a headache 2 days after drinking.

Tension Headaches

Tension headaches are the most common type of headache, with muscle tension and stress as its most common cause. When triggered by alcohol and more specifically the drinks interacting with neural blood vessels, this generally feels like pressure in the head after drinking.

Despite one study linking alcohol consumption to an increase in tension headaches, researchers at the University of Greenwich recently published a contradictory study claiming that drinking 2 pints of beer could reduce pain and possibly improve some headache symptoms. 

When do Alcohol-Related Headaches Happen?

The Headache Classification Committee of the International Headache Society (IHS) divides alcohol-related headaches into two categories based on how long it takes for the headache to happen:

• “Cocktail headaches” are said to be more immediate, occurring within three hours of consuming alcohol.

• “Hangover headaches” are more delayed. These tend to begin between 5 and 12 hours after drinking alcohol.

Generally speaking, a cocktail headache is usually a pulsating or throbbing pain and a hangover headache is more related to fatigue and a general feeling of being run down and tired.

How Much Alcohol Causes an Alcohol-Related Headache?

While some people can get a headache after drinking just a small amount of alcohol, others might require more.

Some factors that contribute to how much alcohol is needed to cause a headache include the type of alcohol being consumed, body weight, gender, and even one’s ethnicity.

Type of Alcohol

The type of alcohol being consumed can determine how little is needed to cause a headache. This is because ingredients and additives used in alcohol production can trigger headaches.

For example, if you're one of the many that report "wine gives me a headache", it's a real issue with some wine manufacturers adding sugar for sweetness, tannins for taste complexity and even sulfites to prevent oxidation and preserve the wine’s color.

Sugar can deplete levels of B vitamins in the body, and tannins and sulfites can cause a histamine reaction in sensitive people. All of these factors will mean fewer drinks before a headache kicks in.

A headache after drinking tequila (especially the cheaper ones) isn't uncommon even among people without sensitivities.  A pounding headache after drinking doesn't necessarily mean you are reacting to alcohol, but it's more likely additives or adulterants added to what you're drinking which is causing the delayed alcohol induced headaches.

Examples of alcohol with less headache causing additives include:

• Vodka
• Gin
• White rum

Drinking these clear spirits straight, with ice, or mixed with soda water may allow headache sensitive people to enjoy more drinks before a headache is triggered.

Body Weight

Generally, a larger person will require more drinks to achieve the same blood-alcohol concentration as a smaller person. Therefore, smaller people might need less alcohol to trigger an alcohol-related headache.

This is particularly the case for migraine sensitive people who have Asian flush. This is because higher blood-acetaldehyde concentrations lead to higher histamine levels in the body and a greater chance of triggering migraines.

In short, if you are a small person with Asian flush, it might require very few drinks to trigger an alcohol-related headache.

Gender

According to a study examining the difference in blood-alcohol levels in women compared to men, the enzyme responsible for breaking down alcohol is smaller in females than in males. With less of this enzyme, women may get alcohol-related headaches from smaller amounts of alcohol compared to men.

Of course, this study doesn’t take into account other factors such as genetics, body size, and even the type of alcohol being consumed. A tall Caucasian woman drinking a vodka soda may be able to outlast a short and skinny Asian man drinking red wine.

Ethnicity

According to a 2009 study about alcohol flush reaction, approximately 30 to 50% of Chinese, Korean, and Japanese people get a red face, nausea, headaches and a rapid heart rate after drinking small amounts of alcohol.

Whilst not exclusive to Asian people, the high proportion of the Asian population affected by this reaction has led to it being called “Asian flush”.

People with alcohol flush reaction lack an enzyme required to break down a toxic byproduct of alcohol metabolism called acetaldehyde. Unfortunately for headache sufferers, acetaldehyde causes the body to produce histamines - a common trigger of migraines.

We talk more about Asian flush related headaches in our article titled 5 Ways to Stop Asian Flush Headaches from Alcohol.

How Can I Avoid Alcohol Induced Headaches?

Fortunately, there’s a lot that can be done to avoid alcohol-related headaches from ruining your night out. From complete abstinence to Asian flush pills, here are a bunch of commonly used tactics that help break down alcohol and protect against alcohol-related headaches:

• Don’t Drink: Yep. Don’t drink alcohol. Choose a fruit cocktail or even a ginger beer. We know that alcohol is not good for our health, so how about choosing a non-alcoholic beverage from time to time?

• Drink Slowly: People sensitive to alcohol-related headaches should space out their drinks. Sip drinks slowly and leave ample time between drinks to allow the body to process the additives and toxins entering the body with every drink.

• Drink Wisely: Choose clear spirits like vodka, gin and white rum. Avoid darker spirits, beer and wine. When choosing mixers, go for zero sugar options like soda water.

• Drink Water: Spacing drinks out with a glass of water in between can ensure adequate hydration and reduce the chances of migraines from dehydration.

• Try Sunset: Sunset contains a variety of ingredients that helps the body break down alcohol and eliminate metabolic toxins that cause alcohol-related headaches.  It's the top rated Asian Flush product on the market with over 4 million nights saved.