Hypernatraemia

Hypernatraemia is an electrolyte imbalance characterized by an abnormally high concentration of sodium in the blood. Sodium is essential for maintaining fluid balance, nerve transmission, muscle function, and normal cellular activity. Hypernatraemia most commonly develops when the body loses more water than sodium, although excessive sodium intake or administration can occasionally contribute.

Common causes include dehydration from vomiting, diarrhoea, excessive sweating, fever, burns, or inadequate fluid intake. It may also occur with kidney disorders, diabetes insipidus, or certain medications that increase water loss. Older adults, infants, and people who cannot access or communicate their need for fluids are particularly vulnerable.

Symptoms depend on the severity and speed of sodium elevation. Mild cases may cause intense thirst, weakness, fatigue, irritability, and dry mouth. More significant hypernatraemia can lead to confusion, muscle twitching, restlessness, seizures, reduced consciousness, and other neurological complications.

Diagnosis is based on blood sodium measurements along with assessment of hydration status, kidney function, urine concentration, and the underlying cause. Treatment focuses on carefully replacing lost water and addressing the contributing condition. Oral or intravenous fluids may be required depending on severity. Sodium levels should generally be corrected gradually under medical supervision to reduce the risk of neurological complications. Early recognition and appropriate treatment can help restore normal fluid and electrolyte balance.