The Truth Behind Headaches and Dehydration

Without a daily intake of water, our bodies wouldn’t be able to function properly and we wouldn’t be able to survive. Water makes up over two-thirds of a healthy human body and plays a crucial role in carrying nutrients and waste products between major organs, regulating body temperature, lubricating joints, flushing out toxins and keeping the skin healthy.[1] Every cell and every function depends on water so it is important to make sure you are hydrated.

If you do not drink enough water your body will be at risk of dehydration. As a general rule of thumb, it is a good idea to drink 1.2 litres of water a day to stay hydrated.[2] The best way to do this is to try and sip small amounts of water regularly throughout the day. By the time you start to feel thirsty you are actually already mildly dehydrated and even mild dehydration can cause a number of problems including tiredness, irritability, light-headedness and headaches.

Often, headaches which are caused by mild dehydration can be relieved quite quickly by drinking a glass of water. Just make sure that you don’t drink too much in one go, as your body could struggle to adjust to a sudden increase in fluids and leave you feeling bloated. Dehydration is also a known migraine trigger, so if you do suffer from migraines make sure you stay hydrated by sipping plenty of fluids throughout the day to help avoid symptoms.
If you do find that you have a headache it is important to make sure that the drink you reach for is water, because the wrong type of drink may also result in further dehydration and could make you feel even worse.


As a well-loved drink and a very important part of some people’s lives, it may be hard to accept but coffee and other caffeinated drinks have been linked as a trigger for headaches and migraines. It is the caffeine in these drinks which is a potential cause for migraines.[3] If you are a regular coffee or tea drinker, it’s best to cut down on your caffeine consumption slowly, as abruptly cutting out caffeine altogether may also lead to headaches.[4]


Alcohol is a diuretic, which means that it actually removes fluids from the body. Drinking too much alcohol can lead to dehydration, which is what causes many of the symptoms we associate with a hangover. Waking up with a nasty headache after having an alcoholic drink the night before, can be an indication that your body is dehydrated. If you decide to drink the best thing to do is limit how much alcohol you consume, alternate with non-alcoholic drinks and drink plenty of water the next day to rehydrate your body.[5]

Not drinking enough water, or drinking too much of the wrong types of drinks can lead to dehydration which may contribute to symptoms of headaches. To help avoid headaches make a conscious effort to stay hydrated by sipping water throughout the day, especially in warm weather and when exercising.