"Hyponatraemia by definition is described as serum Na"
"Development of symptoms in less than 48 hours is called acute hyponatraemia, resulting in fits, impaired sensorium, acute psychosis, permanent brain damage, brainstem herniation, cerebral oedema and coma 2,4."
"Hyponatraemia that persists more than 48 hours is called chronic hyponatraemia; most of the patients are asymptomatic. Possible symptoms include recurrent falls, gait disturbances, and gastric symptoms, including nausea, vomiting, and loss of appetite 2-4."