Sodium
This article is a stub, meaning that it is unfinished. It will eventually be expanded.
Sodium is an abundant electrolyte in the body, and sodium ion (Na+) is the dominant ion in the extracellular space. 65% of sodium is in the extracellular space. Abnormally low or high sodium (hyponatraemia and hypernatraemia, respectively), are common but potentially lethal disorders in the worst case.
Sodium regulation
The level of sodium in the body is regulated by the renin-angiotensin-aldosterone system (RAAS) and by anti-diuretic hormone (ADH).
Sodium in the diet
Too much sodium in the diet increases the risk of cardiovascular disease. Most people today eat much more sodium than is recommended.
Sodium in laboratory medicine
When measuring sodium levels in a blood test, flame photometry or ion-selective electrodes (potentiometry) is used.