This present review analyzes the etiology, diagnostics and management of conditions associated with hyponatremia. Excess water and/or sodium wasting lead to the development of hyponatremia in children. There are diverse etiologies associated with hyponatremia, correct diagnosis is based on detailed history, physical examination and basic laboratory tests. Symptomatic hyponatremia can be a life threatening emergency and thus requires fast and vigorous management. Inappropriate treatment may cause fatal consequences.