Preparation
Sodium (Serum) measures your body's principal electrolyte — the mineral that governs fluid balance between your cells, nerve impulse transmission and muscle function. Sodium is a number doctors watch closely in the sick, the elderly, and anyone on diuretics, because both high and low sodium affect the brain quickly.
Low sodium (hyponatremia) is among the most common electrolyte disturbances seen in hospitals — caused by certain blood pressure medications, excessive plain-water intake in some conditions, vomiting, diarrhoea and hormone problems. High sodium usually reflects dehydration. Symptoms of disturbance range from headache and confusion to weakness and, in severe cases, seizures — always a doctor-supervised situation.
The test is a single home blood draw with no preparation. It is frequently ordered alongside kidney function and other electrolytes; booking them together from one draw gives your physician the complete metabolic picture.
In some situations, yes — drinking far more water than the body is excreting can dilute blood sodium, especially with certain medications or kidney conditions. If you have symptoms like headache or confusion, test and consult a doctor.