“Have you had enough to drink?” Someone's almost certainly asked you this when it's hot, or when you've been exercising or have a headache. However, many people find it difficult to drink the recommended amount every day. Depending on your size and weight, this is between one and two litres. 

The recommended amount of water shouldn't be confused with your total fluid intake, as we also consume fluids through the food we eat. The Swiss Nutrition Association (document in German) recommends a total fluid intake (from drinks and food) of two to two-and-a-half litres per day.

What happens to our body if we don't drink enough water?

"Headaches are probably the most well-known symptom of dehydration," says Ellen Weber, a nutritionist at santé24. Dehydration initially makes itself felt in the form of thirst, discomfort, loss of appetite, nausea, restlessness or increased heart rate. Other effects include a decline in mental abilities such as concentration and reaction times, as well as a reduction in physical performance. 

In the long term, insufficient fluid intake can also increase the risk of constipation, while severe prolonged underhydration can have very serious consequences and will ultimately result in death.

Is it possible to drink too much water?

"You can never drink enough!" Ever heard someone say this? It's actually not true. Studies have shown that when we want to drink without actually being thirsty, our brain resists the urge to swallow. If you drink too much fluid, the salt levels in your body drop, putting you at risk of kidney failure. 

Overhydration can lead to headaches, cramps, dizziness, vomiting or even cerebral oedema. The Swiss Nutrition Association recommends that you should only drink when you feel thirsty. The exceptions here are people who have poor awareness of their thirst or who can't interpret it properly. These groups need to plan to drink at regular intervals.