Until now, it may seem that drinking very large amounts of water is beneficial for the body, but water is uneven. Hyponatremia occurs when you consume much more clean water than you lose or have low electrolyte levels. It is characterized by a low concentration of sodium in the blood serum (< 130 mmol/l). The first symptoms that can be observed are swelling of the feet and hands, followed by wheezing, coughing and encephalopathy with consciousness disorders. In the worst case (<120 mmol/l), death can occur.