What are the consequences of dehydration?

You've all heard of dehydration , but do you really know the consequences ? Do you know how to recognize the effects of dehydration on your body? We'll learn more in this article!

It is true that we often feel thirsty, but it is important to hydrate before it appears, because it is already a sign of dehydration ! In addition, this sensation may not appear at all or disappear after a while. It is therefore possible to forget to hydrate, in which case, dehydration risks worsening. This is why it is essential to ensure that children and the elderly are well hydrated, especially in summer.

The first symptoms are usually subtle : headache , fatigue, dizziness, and confusion. Sometimes you notice a headache after a long day without drinking water, and these sensations go away when you rehydrate.

Weight gain is very important. Weight loss is one of the indicators of dehydration to consider:

• Mild dehydration , corresponding to a loss of 1 to 2% of body weight , leads to a decrease in physical and cognitive performance of up to 10 to 20%. Fatigue then gradually sets in and a feeling of thirst may appear, although it is sometimes absent. Physical signs such as dry mucous membranes , dark circles under the eyes and cold extremities may be observed.
• Moderate dehydration , corresponding to a loss of 2 to 4% of body weight, is manifested by more marked fatigue and a decrease in alertness. The heart rate increases to compensate for the reduction in blood volume, thus leading to tachycardia. The sensation of dry mouth increases, the skin becomes duller and a transient skin fold may appear when lightly pinched.
• Severe dehydration , corresponding to a loss of 5 to 8% of body weight , causes disturbances of consciousness that can range from disorientation to confusion. The decrease in blood volume leads to hypotension and an increased risk of serious accidents, such as fainting or a fall. The skin becomes dry , skin folds persist, the cheeks become hollow and urine production decreases sharply (oliguria).

When water loss reaches 8% or more of body weight, the situation becomes critical and represents a clinically serious case. The risk of coma is high , organs begin to malfunction and limbs become cold to the root, a sign of impending circulatory shock.

What is dehydration?

Dehydration is the result of excessive water and mineral loss that is not compensated for by fluid intake. Since water is essential for many bodily functions, a lack of water causes the effects discussed above.

There are several types of dehydration: extracellular dehydration , intracellular dehydration , and global (or chronic) dehydration . There are common effects to these dehydrations and more specific signs that allow them to be distinguished.

Whatever its form, dehydration should never be taken lightly. Insufficient hydration can quickly affect vital functions and endanger your health.

Most common causes of dehydration

Dehydration can have many origins, and its causes are often similar.

First of all, there are renal losses . These can be due to excessive diuresis (volume of urine evacuated in 24 hours), which is found for example in the case of diabetes . Certain renal insufficiencies or the use of diuretics can also cause significant water loss.

Digestive losses are also a common cause of dehydration that must be addressed quickly. Prolonged diarrhea and vomiting cause rapid loss of water and electrolytes , which can lead to severe dehydration if intake is not quickly replaced.

Skin loss is often underestimated. However, excessive sweating during physical activity or in hot weather is a major cause of dehydration. Fever and heatstroke also increase water loss.

Pulmonary losses , although less visible, can contribute to dehydration, as a quantity of water is evacuated in the form of vapor. This phenomenon is accentuated in the event of hyperventilation , particularly during sports, contributing to the loss of body water.

Other external factors can contribute to dehydration , and excessive alcohol consumption is a prime example. Alcohol reduces the efficiency of the kidneys, which increases the frequency of urination to compensate.

What are the symptoms of dehydration?

Dehydration can affect different parts of the body, causing varying symptoms depending on whether it is extracellular or intracellular.

Symptoms of extracellular dehydration

What is this ? Extracellular dehydration results from a loss of water at the extracellular level (plasma and interstitial fluid). While the volume of intracellular water remains the same, an effective extracellular osmotic pressure is maintained.

Extracellular dehydration initially manifests as significant fatigue, poor appetite , and a lack of thirst, which can delay fluid intake and worsen the condition. Unlike intracellular dehydration, the mucous membranes remain moist, but slight weight loss may be observed due to the decrease in plasma volume.

Clinical examination reveals flat peripheral and jugular veins, as well as cool, discolored extremities , indicating low central venous pressure. Hypotension occurs, causing dizziness and an accelerated pulse to maintain adequate organ perfusion. Skin tone is altered, with persistent skin puckering, particularly in the abdomen, infraclavicular region, and inner thighs (this sign, however, can be difficult to interpret in the elderly).

The eyeballs appear sunken, a sign of a certain water deficit. In cases of severe extracellular dehydration, the clinical condition worsens with very low blood pressure (less than 80 mmHg), cold extremities and the presence of mottling on the skin, indicating an imminent state of shock requiring urgent medical attention.

What are the risks? Severe extracellular dehydration can lead to a significant drop in blood pressure, limiting oxygen delivery to organs and causing hypovolemic shock. The kidneys, lacking water, significantly reduce urine production or risk acute renal failure . Without prompt treatment, these complications can be life-threatening. We therefore advise you to make an appointment with a healthcare professional as soon as possible!

Symptoms of intracellular dehydration

Intracellular dehydration occurs when the intracellular sector becomes dehydrated because there is an increase in plasma osmolarity (usually an excessive sodium concentration in the blood) that the body has compensated for by sending water from the intracellular sector into the plasma to dilute the excess sodium and thus restore water balance . This loss of intracellular water causes a contraction of cells, particularly impacting those of the brain and muscles.

One of the first signs of intracellular dehydration is intense, uncontrollable thirst, as the body desperately tries to compensate for the water deficit. As the condition worsens, impaired consciousness develops, ranging from confusion to deep coma in the most extreme cases.

Weight loss can be significant, reaching up to 20% of body weight, a sign of severe water deficiency. This dehydration is often accompanied by fever and rapid breathing, which exacerbates water loss.

Other signs can help identify this form of dehydration. The mucous membranes are dry and the tongue is retracted. A medical examination can also reveal neurological disorders, a direct result of brain cell shrinkage.

What are the risks? Severe intracellular dehydration can have serious effects , especially on the brain . When cells lose too much water, they shrink, which can cause memory problems, concentration problems, and confusion. In the most serious cases, this can lead to loss of consciousness or coma.

In infants and the elderly, the brain is more fragile, and this dehydration can sometimes cause a small cerebral bleed (subdural hematoma). If it lasts too long, it can leave after-effects on intellectual and motor abilities.

How to treat dehydration?

Adult, child, infant, different treatment?

To rehydrate , the principle is the same for everyone: drink to recover lost water and restore electrolyte balance . However, the method of administration and management vary depending on age and the severity of dehydration.

For an infant, for example, oral rehydration solutions (ORS) are necessary. These solutions, specifically designed to replenish fluid and electrolyte losses , are the best option because babies have difficulty expressing thirst and cannot regulate their own hydration.

For an older child, rehydration can be achieved through ORS , but also through feeding them foods rich in electrolytes such as salt (sodium) or banana (potassium) . However, it can be difficult to get them to drink a large amount of water. If dehydration is mild to moderate, encouraging them to drink small amounts but frequently is an effective approach. If the child refuses to drink plain water, alternatives such as slightly sweet and salty drinks, broths, or water-rich fruits (watermelon, cucumber, etc.) can be used.

For an adult, all methods are suitable, and it is easier for them to assess their condition and measure their water intake. However, severe dehydration should not be overlooked, as it may require urgent treatment!

What solutions?

Severe cases and intravenous solution

If severe dehydration is looming, consulting a doctor or going to the hospital is essential. In terms of care, there are several options for treating the patient: first, direct control of the amount of fluids to be drunk. Indeed, controlled oral rehydration is necessary, under medical supervision, to avoid any osmotic imbalance.

Then, in the worst cases (repeated vomiting, impaired consciousness, hypovolemic shock, etc.), it is possible to resort to the intravenous administration of a sodium chloride solution.

SRO

ORS is the gold standard for treating mild to moderate dehydration, particularly in infants and young children. Recommended by the WHO , they allow for rapid absorption of water and electrolytes through the combination of sodium and glucose. They are particularly effective in cases of diarrhea, gastroenteritis, or fever, when the child loses a significant amount of fluid.

In adults, rehydration relies more on regular water consumption, including drinks containing sodium, potassium, and glucose to improve intestinal water absorption and fluid retention. There are several solutions, from the most basic, such as sugar and salt water, to solutions that optimize the effects on the body with other supplements, such as trace elements, as offered by Hydratis.

Why use Hydratis?

Hydratis is a hydration solution composed of sugars, electrolytes and trace elements, designed to improve hydration in cases of fatigue , intense physical exertion , hot climate or sports recovery. It is based on WHO recommendations and suitable for the greatest number of people.

Its practical format and different flavors, to suit everyone, make it a pleasant alternative to traditional solutions, while providing rapid and targeted hydration.

5. Some tips to prevent dehydration

To prevent dehydration, there are two main conditions to respect:

First, make sure you maintain a good electrolyte balance . This can be done simply with a varied diet, or ORS.

Then, you obviously need to drink enough water , beyond just listening to the sensation of thirst. This is particularly important for fragile people (young people who can hardly judge their condition or quench their thirst on their own, and the elderly for whom the effects of dehydration are amplified) and for athletes, who lose water much more quickly through perspiration and exhalation. ORS such as Hydratis are ideal, also offering different flavors. If you want to use tap or bottled water, ANSES offers an effective infographic to remember the most important things.

Bibliography

Bottled water or tap water: good consumption practices - ANSES

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