How to be well hydrated on a daily basis?
Water, the main constituent of our body, is essential for its functioning. At a moderate ambient temperature and at rest, the body always maintains its water quantity at a constant level. It is able to react to variations in water intake and loss to maintain a water balance . If the balance is broken and the body loses more water than it receives, then dehydration sets in. Dehydration is therefore the state that results from a lack of water in the body and which occurs when the body loses more water than it acquires.
How do you get dehydrated naturally?
Every day, our body eliminates water, mainly through urine and sweat, but also through evaporation from the skin, breathing and stools.
These losses vary depending on physical activity, temperature and consumption of fluids and food.
Water is mainly eliminated through urine , a product of the filtration of blood by the kidneys used to get rid of liquid waste from the body. The body thus eliminates from 500 ml to several liters of water per day.
Water loss is also due to perspiration , which helps regulate and maintain a constant body temperature. Sweat, excreted by the sweat glands on the surface of the skin, lowers the body's internal temperature. It is composed of 99% water and minerals, waste (urea, uric acid) which are therefore lost during perspiration. Perspiration varies depending on physical activity, outside temperature, humidity, body temperature, clothing, etc. We must therefore adapt our water consumption according to the circumstances.
The body naturally loses water through cutaneous evaporation . Water hydrates the skin by diffusing from the dermis (the lower part) to the epidermis (the upper part) and then evaporates. In adults, this loss is approximately 450 ml per day, it varies with the temperature and external humidity but is most often imperceptible.
Breathing also causes water loss, about 250-300 ml per day at rest. They increase with physical activity, altitude, lower temperature and humidity.
Finally, water losses through stools are low in a healthy adult, at a rate of 200 ml per day.
If natural, daily water losses are not compensated by sufficient hydration, the body becomes dehydrated.
What causes dehydration?
The causes of dehydration are multiple, certain situations, pathologies or people are more at risk.
Common occasions
Excessive sweating during a heat wave, during intense and prolonged exercise or during a fever can cause dehydration.
Certain drinks such as alcohol, coffee or tea increase diuresis and can cause dehydration.
Alcohol is often thought to quench thirst, but this is a misleading sensation. In reality, alcohol has diuretic properties that can contribute to maintaining a state of dehydration. This results in a dilution of urine and an increase in urine output. Excessive consumption of alcoholic beverages causes the body to "waste" water to eliminate the alcohol. Alcohol-related dehydration amplifies hangover symptoms such as dry mouth, intense thirst and headaches.
During the menstrual cycle, estrogen and progesterone hormone levels fluctuate, which affects the body's hydration and can lead to episodes of dehydration. Blood loss during menstruation further compounds this dehydration.
Other situations, such as periods of fasting, can cause temporary fluid restrictions. Care must be taken not to allow dehydration to set in.
The pathologies
During episodes of gastroenteritis, diarrhea and vomiting cause significant water loss and the situation can become serious if there is not sufficient fluid replacement, with the person feeling too ill to drink enough fluids.
Chronic diseases, such as diabetes , can increase urinary excretion and therefore lead to dehydration.
Taking medications such as diuretics or taking excessive laxatives can lead to dehydration. Diuretics increase urine excretion and the loss of electrolytes (mineral salts such as sodium, potassium or chloride) in the urine.
People at risk
Anyone can be prone to dehydration, but some people are at higher risk. Those who engage in intense physical activity, for example, professional athletes. Older people are also particularly prone to dehydration, because the thirst center functions less well than in younger people. Infants and children are at risk of dehydration, their bodies are very rich in water and losses due to diarrhea or vomiting represent a greater proportion of fluids than adults.
What are the consequences of dehydration on the body?
The first sign of dehydration is the feeling of thirst , a signal from the body telling us that it is necessary to drink more. With dehydration, blood volume decreases and this drop in volume will trigger the feeling of thirst in response. But by the time thirst is felt, the body is already dehydrated.
Mild to moderate dehydration can be seen in low energy, fatigue, difficulty concentrating, mood swings, and headaches because the body and brain are less hydrated and therefore perform less efficiently. Skin tissues are also less hydrated and lack electrolytes, causing redness, dryness, and tightness of the skin and dry, pasty mouth.
Dehydration leads to a decrease in diuresis (therefore a decrease in urine volume) and more concentrated and therefore darker urine.
Cramps, involuntary contractions of muscles at rest, during sleep or during physical exertion, occur due to poor hydration and lack of mineral salts.
Finally, dehydration promotes constipation. Indeed, the stools are no longer softened enough by water, intestinal transit is slowed down and the stools become harder.
If water loss is not replaced by fluid intake , dehydration becomes more severe . Tissues dry out and body cells begin to malfunction. You may feel confused, dizzy due to low blood pressure, or faint. In severe cases, all cells in the body become dehydrated, leading to damage to organs such as the brain, kidneys, or liver.
To prevent these consequences, any water loss must be compensated by food, which represents 20 to 30% of water intake, and drinks (70 to 80%), for a recommended intake of around 1 to 1.5 L of water per day.
