Hyponatraemia

Patients taking selective serotonin-reuptake inhibitors or thiazide diuretics, and those with heart failure, malignancy (especially of pulmonary origin), cirrhosis, or nephrotic syndrome should be advised to avoid excessive water intake and may benefit from regular monitoring of their weight. Patients should be educated about the signs and symptoms of hyponatraemia, including nausea, vomiting, lethargy, and seizures. The importance of compliance with follow-up appointments and laboratory work is emphasised.

In the absence of thirst, excessive water intake should be avoided during marathons, other extensive exercise, and dieting. There are no data to support a goal of drinking 8 glasses of water each day except for certain circumstances such as in the setting of nephrolithiasis.