Can Excessive Water Intake Be Dangerous?

There are circumstances in which excessive consumption of water can lead to negative health consequences. It should be noted immediately that not only water, but also other beverages with lower osmolality than body fluids are the cause. Hypotonic beverages (such as water) lead to dilution of the blood, particularly plasma, which reduces the concentration of minerals, such as sodium. The state where the sodium level in blood plasma is low (below 130 mmol/l, norm is 135-144 mmol/l) is called hyponatremia, which poses a potential threat to human health and life.

Sodium, in the form of sodium ions, is vital for transmitting nerve impulses, maintaining osmotic equilibrium in extracellular fluids, transporting nutrients to tissues, preserving the body's acid-base equilibrium, and enhancing the secretion of digestive juices. Symptoms of sodium ion deficiency include fatigue, restlessness, disorientation, headache and vomiting, edema of the lower extremities, brain, and lungs, respiratory distress, drowsiness, and in extreme cases, death.

Hyponatremia can be induced by excessive intake of water or other hypotonic beverages, leading to sodium loss. Involvement in competitions aimed at consuming the maximum amount of water can have fatal consequences. Certain individuals excrete more sodium, which manifests as noticeably salty secretions and salt residues on skin and clothing, along with eye irritation from perspiration.

The avoidance of hyponatremia also involves replenishing fluids after exercise in proportion to losses. You can compare your body weight before and after exercise to determine the amount of fluid you should take in. For every 1 kg of weight loss, you should consume 1.5 liters of fluid. You don't have to drink more. You shouldn't drink such a large amount of fluid all at once, but rather spread it out over time and drink smaller portions of 300-400 ml. The body is capable of absorbing such amounts of fluid at once. A low sodium concentration in plasma triggers a protective mechanism in the body that reduces thirst. This is a signal that the body does not want to take in any more fluid to protect the sodium concentration in the plasma. Athletes often ignore this mechanism and give their bodies fluids before they feel thirsty during exercise. In this way, they can prevent premature dehydration and a decrease in performance. However, it is important not to overdo it and follow a reasonable fluid intake strategy. In the prevention of hyponatremia, it can also be helpful to replace hypotonic beverages (including water) with isotonic beverages during the peri-exercise period. Such fluids do not dilute the blood, and their osmolality is comparable to that of plasma. In addition, isotonic beverages usually contain sodium in amounts of 460-1150 mg/l, so they hydrate well and at the same time compensate for sodium loss.