How much fluid does the body need?

Water is essential. More than 50 percent of the human organism is made up of water – in children about 70 percent. The fluid is constantly excreted through the skin, intestines (stool), kidneys (urine), and breathing. Therefore, the liquid must be taken continuously. Adults should drink at least 1.5 liters of water from beverages daily. If you drink too little, you should expect a decrease in physical performance.








Water has many different functions. They are found in every cell in the body and all body fluids – for example in saliva, stomach juice, lymph or blood. Among other things, water is necessary to maintain heat regulation (sweating). Transport of nutrients, metabolic end products, and respiratory gases depends on water. All chemical reactions in the body also require water.

Daily fluid requirements

The need for water varies and depends, among other things, on energy consumption, ambient temperature and food composition. For example, the percentage of table salt is important. Depending on their age, teens and adults should take between 30 and 40 ml of water per kilogram of body weight daily.

As a guideline for healthy adults, furthermore: about 1 ml of water per 1 calorie per day. At 2,500 calories, this results in 2.5 liters per day for an adult. Adults should consume at least 1.5 liters of fluid from beverages per day.

What are the appropriate drinks?

Low-energy drinks such as water, mineral water, unsweetened fruit and herbal tea as well as diluted fruit and vegetable juices. Coffee and black tea should be drunk in moderation (maximum 3 to 4 cups).


Can you drink too much?

Water intoxication (poisoning) is very rare, but can occur if the kidneys' excretion capacity is excessive. The maximum fluid intake that adults can take daily in the long term is about ten litres.

Symptoms of excessive water intake include the following

Difficulty breathing (dyspnea)
Water retention in tissues (edema)
Convulsions, confusion, loss of consciousness, even coma
Symptoms of heart failure
Rapid heartbeat (tachycardia)

Certain diseases (such as kidney weakness) are usually responsible for overhydration

What happens if there is a lack of fluid?

Lack of water quickly leads to severe damage. The urinary system no longer excretes urine after two to four days. If too little water is taken, poor concentration, headache, decreased physical performance and - especially in the elderly - confusion may occur. Since fluid deficiency is also noticeable in the intestines, constipation is another possible effect. In the worst cases, circulatory failure can occur due to lack of water.

The need, for example, increases during physical exertion, during exercise, at very high or low temperatures and when fever, vomiting and diarrhea occur. You should take more water during pregnancy and breastfeeding.

Fluid deficiency quickly manifests itself through various signs. Depending on the extent of the defect, this includes:

thirst
Dry mouth, decreased production of saliva and urine,
headache,
Weight loss,
decreased skin tone, swelling of the tongue, difficulty swallowing,
holding,
Accelerated heartbeat, increased body temperature,
Thick blood
Severe limitation of physical and mental performance, confusion,
Muscle spasms as well
Circulatory collapse.

Without fluid replacement -> life-threatening