You can overdose on water. Doctors recommend how much to drink.

As temperatures rise, so does thirst. Many people believe they need to drink huge amounts of water during hot weather. It might seem that the more, the better.

Meanwhile, doctors warn that too much water can be just as dangerous as too little. While proper hydration is essential, excessive drinking can lead to electrolyte imbalances. Elderly people, those with chronic illnesses, and athletes in particular should be alert to warning signs.

The German Nutrition Society recommends consuming around 1.5 liters of water per day, but actual needs depend on many factors: ambient temperature, physical activity, perspiration, and health status. Thirst increases after salty snacks and sweets, while vegetables and fruit support hydration.

Too much water is a real risk

Dietitian Hannah Hauser from Frankfurt warns that so-called "rigid drinking rules" can lead to bad habits. One example is drinking water before every meal to lose weight. She believes that drinking just to satisfy perceived hunger can mask the body's true needs—for example, insufficient calorie or mineral intake. Adding water can then only worsen the situation.

Human kidneys can filter approximately 0.8 to 1 liter of water per hour. Consuming larger amounts within this timeframe can result in hyponatremia – a dangerous drop in blood sodium levels below the normal range (135–145 mEq/L).

Sodium regulates the water balance of cells and the spaces between them. Its deficiency results in headaches, dizziness, swelling (for example, of the brain and lungs), and in extreme cases, coma or death.

Sports, parties, and illness. When does water become the enemy?

Even healthy people can overdose on water, such as long-distance runners who compulsively drink during competitions. This often results in seizures or cerebral swelling.

Meanwhile, during festivals like Oktoberfest, participants consume liters of fluids in a short period of time—not just alcohol. The body can't process it. The kidneys can't keep up, circulation weakens, and blood pressure destabilizes.

Fluid regulation is impaired in old age. Seniors often end up in hospitals due to water intoxication, as sodium levels drop dramatically. Professor Clemens Cohen from Munich warns that this condition can lead to serious neurological disorders. People with hypothyroidism are also at risk. This condition increases sodium loss in the urine, and excess water further disrupts electrolyte balance.

Patients with heart or kidney disease also need to exercise moderation, typically limiting fluids to 1 liter per day. The body retains sodium, which binds to water, which can cause swelling and shortness of breath. Often, the only signs are weight gain or a dimpled skin sensation when pressed.

How can we tell if we drink too much?

Your own body is the best indicator. Hauser advises trusting your thirst and paying attention to symptoms: fatigue, nausea, muscle cramps, or headaches can be warning signs. The color of your urine also speaks volumes – white or very light can indicate excess water, while dark yellow signals dehydration.

It's recommended to drink tap water (preferably filtered), and minerals are best supplemented through a varied diet. For physically active people, coconut water or water with orange juice and a pinch of salt is recommended.

Professor Cohen warns against the trend of carrying a water bottle around all day. The habit of constantly drinking can be dangerous when you're sick. It's also better to drink water gradually throughout the day, rather than "stocking up" in the evening.

Read also: Do you drink water with your food? Find out what's really going on in your body. Read also: Do you have it at home? Dangerous bacteria in popular water! It's better not to drink it, because you're risking your health.