Sodium

Sodium is an essential nutrient that plays a key role in regulating fluid balance, transmitting nerve signals, and enabling muscle contractions. In the human body, the majority of sodium is located in the bloodstream and in the fluids surrounding cells. Keeping sodium levels within a healthy range is vital, since both too much and too little can lead to serious health issues. The kidneys serve as the main regulators of sodium concentration. When blood sodium rises, they promote its elimination in urine; when levels drop, they conserve sodium by limiting its excretion. This regulation relies on intricate processes of filtration and reabsorption, guided by hormonal control, most notably aldosterone, which directs the kidneys to retain sodium. Proper sodium regulation helps sustain normal blood pressure, prevents dehydration, and supports the smooth operation of many essential bodily functions.