Hypernatremia

CLINICAL DIAGNOSTIC MANUAL

Hypernatremia is defined as an increase in plasma sodium concentration above 145 mmol/L. This electrolyte imbalance occurs when there is a net water loss relative to sodium or a net gain of sodium.

Hypernatremia can be dangerous and potentially life-threatening, as it can cause cellular dehydration, particularly in the brain, leading to severe neurological symptoms.

Proper management of hypernatremia involves identifying and treating the underlying cause, as well as carefully correcting the water imbalance to prevent complications.

Pathology	Clinical Symptoms and Signs	Suspected Diagnosis	Confirmatory Diagnosis
Hypertonic plasma with hypervolemia	Edema, hypertension, weight gain, intense thirst, confusion, muscle weakness	History of hypertonic solution administration	Serum electrolyte measurement, plasma osmolality
Hypovolemia	Orthostatic hypotension, tachycardia, dry skin, intense thirst, confusion	History of fluid loss (diarrhoea, vomiting, sweating)	Serum electrolyte measurement, urinary osmolality, BUN/creatinine
Diabetes insipidus with hypovolemia	Polyuria, polydipsia, orthostatic hypotension, tachycardia, confusion	History of polyuria and polydipsia, dilute urine analysis	Water restriction test, ADH measurement, urinary and plasma osmolality
Primary aldosteronism due to adrenal hyperplasia	Hypertension, muscle weakness, cramps, polyuria, polydipsia	History of resistant hypertension, serum electrolyte analysis	Serum aldosterone and renin measurement, saline suppression test, abdominal CT or MRI
Conn’s syndrome with adrenal tumour	Hypertension, muscle weakness, cramps, polyuria, polydipsia	History of resistant hypertension, serum electrolyte analysis	Serum aldosterone and renin measurement, saline suppression test, abdominal CT or MRI, hormonal evaluation