"The difficulty lies, not in new ideas but escaping old ones, which ramifies, for those brought up with them, as most of us has been, into every corner of our minds" - John Maynard Keynes Hyponatremia is defined as serum sodium concentration less than 135 mmol/L. Biochemical severity of hyponatremia has been described as mild (S. Na of 130-135 mmol/L), moderate (125- 129 mmol/L) and Severe/ profound (125 mmol/L). Clinical severity of hyponatremia is recognized based on urgency of treatment. Severe symptoms are the result of cerebral edema and increased intracranial pressure with risk herniation. It manifests as vomiting, seizures, obtundation and cardiorespiratory distress. Moderately severe symptoms of hyponatremia are due to mild cerebral edema but no risk of herniation. Clinically it presents as headache, nausea and confusion. Hyponatremia is classified as acute and chronic depending upon time profile of existence.