hormonal and metabolic disorders
Overview of Sodium's Role in the Body
Maintaining fluid and sodium balance in older adults
As people age, the body is less able to maintain fluid and sodium balance for several reasons: Decreased thirst:As people age, they sense thirst less quickly or less intensely and thus may not drink fluids when needed. Changes in the kidneys:Aging kidneys may become less able to reclaim water and electrolytes from the urine (concentrate urine), and, as a result, more water may be excreted in urine. Less fluid in the body:In older adults, the body contains less fluid. Only 45% of body weight is fluid in older adults, compared with 60% in younger people. This change means that a slight loss of fluid and sodium, as can result from a fever or from not eating and drinking enough (sometimes for only a day or two), can have more serious consequences in older adults. Some older adults have mobility or other physical challenges that prevent them from getting something to drink when they are thirsty. Others may have Dementia , which may prevent them from realizing they are thirsty or from saying so. They may have to depend on other people to provide them with water. Many older adults take medications for High Blood Pressure , The above situations can result in losing fluid or not consuming enough fluid and thus can cause a high sodium level in blood ( Hypernatremia (High Level of Sodium in the Blood) ) and/or fluid and sodium also occur more commonly in older adults because disorders that usually result in excess fluid ( Overhydration )— A low sodium level in blood ( Hyponatremia (Low Level of Sodium in the Blood) ) is more common among older adults. Hyponatremia usually results when the body retains too much fluid, as occurs in heart failure or liver disease. Hyponatremia also occurs in older adults who take certain types of diuretics (thiazide diuretics such as 