Sodium is an essential mineral found primarily in bones and extracellular fluid. It is required for muscle function, heart beat initiation and maintenance of fluid balance. The daily recommended intake is 5-10g but many consume more than required due to salt's flavoring properties. The kidneys regulate sodium levels by filtering it from blood and reabsorbing almost all of it. Both low (hyponatremia) and high (hypernatremia) sodium levels can occur due to various diseases, hormone imbalances, or prolonged medication use. Common causes of hyponatremia include Addison's disease while hypernatremia can result from Cushing's syndrome or prolonged corticosteroid administration.