Can drinking too much water be harmful?

Optimal athletic performance and full concentration: Water is vital for all processes in the body to run smoothly. This is also evident from the fact that we could survive for a month without solid food, but only a few days without water. But can too much fluid also harm the body? We'll show you in our new blog post.

Water is important

Water is quantitatively the most important component in the human body. It enables the transport of numerous substances and is a reaction partner in many metabolic processes. It is also involved in the regulation of the acid-base balance and body temperature. Drinking too little therefore quickly becomes noticeable: Poor concentration, tiredness and headaches are the result.

On average, an adult consists of up to 70% water. Around 2.5 litres are lost every day through excretion, respiration and the skin. This loss must be compensated for. On average, we take in around 1.5 litres through drinks, almost 1 litre through food and small amounts are produced when food components are metabolised. For example, the metabolisation of 1 g of carbohydrates produces 0.6 ml of water, 1 g of protein 0.42 ml and 1 g of fat 1.07 ml. So how much liquid is actually necessary?

Can too much fluid harm the body?

The best sign to drink a glass of water is your own feeling of thirst. However, ignoring this feeling and drinking a lot of water (6-7 litres) in a short space of time can have serious consequences for your health. Depending on the severity, headaches, tiredness, lack of concentration, dizziness and nausea can occur. In more severe cases, seizures and even coma can occur. The reason for this is that the kidneys can no longer process the large amounts of fluid. As a result, the electrolyte balance is unbalanced and important minerals are flushed out of the body. This leads to hyponatraemia. This means that the salt concentration in the blood drops dramatically. As a result, water is channelled into the cells and the formation of oedema is promoted. Such swelling has life-threatening consequences, especially for the brain. The immediate solution is therefore to compensate for the existing salt deficiency.

Strict control of the amount drunk is exaggerated

It must be clearly stated that there is no danger of drinking too much, either in everyday life or during exercise. This is because the body can process around 10 litres of water a day without any problems and excrete it in the urine. Deaths have only occurred with very large amounts of water. In 2014, two 17-year-old US football players died due to a severely swollen brain because they each drank around 15 litres of water (!) during training.

How much fluid should you drink?

During the day, you should drink at least 1.5 litres of fluid evenly distributed throughout the day. In hot temperatures and during physical activity, when you sweat more, you should drink even more. You also need to compensate for water loss if you have a fever, vomiting or diarrhoea.

P.S.: It's also important that you don't just drink when you feel thirsty. This is because thirst is a sign that you already have a fluid deficit.

• Biesalski H. K. and Grimm P. (2004) Pocket atlas of nutrition. Thieme Verlag, 4th edition, Stuttgart.
• Köhnke K. (2011) Der Wasserhaushalt und die ernährungsphysiologische Bedeutung von Wasser und Getränken. In Ernährungsumschau 2/2011, Bonn.
• https://www.welt.de/gesundheit/article110187381/Wie-viel-Wasser-ist-wirklich-gesund.html