Many of us depend on coffee to perk us up in the morning, but it also has other effects on top of the obvious energy boost.

One unwelcome effect of drinking coffee is that it can lead to headaches, even when drunk in small amounts. And if this is you, there’s every chance it could be as a result of an intolerance to caffeine.

In some cases, in those without caffeine intolerance, coffee can also have the opposite effect and has been found to alleviate headaches.

The caffeine in coffee is what gives you that pick-me-up. By both blocking a chemical called adenosine – known for making you tired – and releasing adrenaline into your body, it gives you an increase of energy and alertness.

When consumed in large amounts, coffee will give many people a headache, whereas those with a caffeine intolerance will feel the effects after just a cup or less.

But what is it about coffee and caffeine that causes headaches?


How caffeine causes headaches

Caffeine may give you an energy boost, but it also encourages bodily functions – bowel movements and urination – which can potentially dehydrate you and lead to a headache. 

Caffeine will also make the blood vessels in your brain constrict, which will then dilate once you stop drinking it. This change in blood flow to your brain is another reason you may experience a headache.

Each of these can be caused by a small amount of coffee – just one or two cups. However, you’re much more likely to experience a headache from coffee the more you drink.

Unfortunately, sometimes caffeine and headaches go hand-in-hand, and if so it’s another reason to suspect that you may have an intolerance. With caffeine intolerance, you’ll likely experience headaches or other effects even after consuming just a small amount.


How much caffeine should you have in a day?

It’s recommended that you have no more than 400 milligrams of caffeine per day, however, this can vary depending on your own tolerance levels.

Caffeine is also found in other food and drinks, so be aware that you may be ingesting it in other ways, such as with tea, soft drinks, energy drinks, and chocolate. Even decaf coffee contains a small amount of caffeine.

If you suspect you may have an intolerance to caffeine, you’ll feel similar effects to drinking and eating the above as you do when drinking coffee.


Understanding caffeine withdrawal

Another reason you can get a headache due to coffee is by experiencing caffeine withdrawal.

If you usually drink a certain amount of coffee in a day, maybe as part of your workday routine, you may find that during periods when you drink less you experience a headache.

That’s because your body gets used to the caffeine in coffee, and so by taking it away you’re going to experience withdrawal symptoms – with one of those being a headache.


How to help ease a caffeine headache

If you’re feeling the effects of a caffeine-induced headache, there are a number of ways you can help reduce the symptoms:

  • Drinks plenty of water
  • Take an over-the-counter painkiller such as paracetamol
  • Get some sleep
  • Avoid overexposure to bright lights or screens
  • Use an ice pack
  • Massage your pressure points


How coffee and caffeine can also help with headaches

Caffeine is also known to help ease headaches. In fact, caffeine is even found in some over-the-counter painkillers.

For those suffering a headache caused by caffeine withdrawal, a small amount of caffeine is one way to relieve a headache. In the event that caffeine helps ease your headache, it’s unlikely that you have any sort of caffeine intolerance.


What are other symptoms of caffeine intolerance?

Around 10% of the population has an intolerance to caffeine, which is either genetic or triggered by changes in the liver, and is caused by the body metabolising caffeine much slower than it does in others. If you have a sensitivity to caffeine it can have a number of effects on the body, including:

  • Headaches
  • Heart palpitations
  • Rapid heartbeat
  • Anxiety
  • Insomnia
  • Restlessness
  • Tremors

If you experience any of these effects after drinking coffee or any other caffeinated drinks (or food) then it’s likely that you have an intolerance to caffeine. 


How can I see if I have a caffeine intolerance?

If you suspect you have a caffeine intolerance, it’s important to get this confirmed so you know what you can and can’t consume. Pinpointing a food intolerance is the first step in ensuring you stay healthy and don’t risk aggravating it or experiencing any of the unpleasant side effects,

It’s possible to test whether or not you have a caffeine intolerance at home by ordering a complete sensitivity test.


Drink coffee in moderation

Even for those of us without a caffeine intolerance, coffee should still be drunk in moderation, making sure not to exceed the recommended 400 milligrams per day – which is roughly 4 cups.

It can be easy for our bodies to become dependant on the energy boost coffee gives us, which can also lead to withdrawal when it’s taken away. If coffee is giving you a headache, try limiting your intake or switching to decaf, and take a food intolerance test to check if you have an intolerance to caffeine.

If you think you may have caffeine intolerance, browse our tests so you can check for yourself at home.