Water intoxication is a potentially fatal condition, which essentially occurs due to overhydration that causes an imbalance in the level of electrolytes.
In the initial stages, the signs and symptoms of water intoxication may be insignificant and resemble some common illnesses. Affected individuals usually vomit, experience headache and also develop certain changes in mental state, characterized by confusion and disorientation .
In the advanced stages of the disease, water intoxication can cause the sodium levels to drop dramatically which can lead to weakening of muscles, spasms and muscle cramps. Affected individuals can also experience seizures, followed by state of unconsciousness and finally coma  .
Infants or babies affected by water intoxication, exhibit signs of inattentiveness, irritability and drowsiness as part of altered mental state. They may also experience difficulty in breathing, muscle cramps and spasms, twitching along with blurred vision. The face of the affected babies may swell, following a slight drop in their body temperature.
A past medical history about disease and drug profile will be gathered, followed by physical examination of signs and symptoms. However, physical examination alone would not be sufficient to diagnose the condition of hyponatremia that has occurred due to water intoxication. Therefore, a complete blood profile along with urine tests to determine the levels of sodium level would be required.
Blood tests to assess drug intoxication and underlying disease conditions such as diabetes would also form an important part of diagnostic procedure. Along with this, mental health screening for determining presence of psychiatric illness is also indicated .
In the initial stages, restricting fluid intake forms the basis of treatment regime in order to correct hyponatremia. This is followed by treating underlying disease conditions. The patient would also be put on diuretics in order to improve the sodium levels. In more severe cases, hospitalization would be indicated. Intravenous administration of sodium is indicated to increase the serum sodium levels. Medications would also be required to effectively manage the symptoms associated with water intoxication .
Prognosis of patients suffering from water intoxication is fairly good if the condition is promptly treated when the first signs and symptoms appear. However, delay in initiation of treatment can call for irreversible damage to set in and eventually cause death.
Excessive consumption of water knowingly or unknowingly can cause overhydration to set in. Certain medications can increase the thirst in individuals which can eventually cause an increased consumption of water. Increase in thirst mechanism can also be an indication of some underlying disease condition such as diabetes. Psychiatric illnesses can also lead to compulsive drinking of water. In addition, other risk factors for water intoxication include low body mass in infants, heat stress or overexertion, iatrogenic and drinking water for some sort of competition. Individuals who adhere to a strict dietary regime for intentional weight loss, where they are required to consume more water are at an increased risk for developing water intoxication  .
According to various research studies carried out across the globe, it was reported that water intoxication can be a significant cause of mortality amongst patients suffering from schizophrenia. Of 353 patients under a study, about 38 were found to be polydipsic and one third of them was at an increased risk of water intoxication.
In the condition of water intoxication, the electrolyte content in the fluid outside the cells is extremely low in contrast to what is present inside the cells. Such a kind of phenomenon causes the fluid to shift, in order to balance the concentration. This in turn causes the cells to swell, which eventually increases the intracranial pressure. This is what gives rise to the preliminary signs and symptoms of water intoxication. If the condition is not corrected, then the brain cells further undergo swelling giving rise to cerebral edema which occurs due to interruption in blood flow .
Individuals are advised against drinking more than 1 litre of water per hour. Appropriate hydration prior to participating in race or any other strenuous activities can also help prevent excessive drinking of water. Athletes are also advised to sip in sports beverages containing sodium and potassium. These would help replenish the lost electrolytes. Individuals are also advised to consult doctor if they experience a strong desire to drink water or are excessively thirsty .
The condition is also termed as dilutional hyponatremia. Just like any other substance, water too can turn poisonous for the body if consumed beyond limits. It has been estimated that majority of death that have occurred due to water intoxication have resulted from excessive consumption of water by individuals who are either participating in contests or by athletes who after heavy exercise have consumed large amounts of water .