Elderly patients with low sodium levels are usually asymptomatic, although headaches, nausea, confusion and respiratory arrest show up in severe conditions, according to Kugler and Hustead for the American Family Physician journal from the American Academy of Family Physicians. If the condition develops quickly, it may cause muscle twitching and irritability, while chronic cases may cause lethargy and malaise.
Low sodium levels, or hyponatremia, is a condition where the homeostatic balance of water and sodium is upset, resulting in very little sodium or too much water in the blood, explains Kugler and Hustead. Causes of hyponatremia include true volume depletion, hypothyroidism, reset osmostat syndrome, glucocorticoid deficiency, drugs such as hydrochlorothiazides and the syndrome of inappropriate antidiuretic hormone secretion, or SIADH. Elderly people are highly susceptible to hyponatremia because factors, such as a lifetime of accumulated diseases and age-related physiological changes, may impair renal function, the thirst mechanism, concentration abilities and hormonal regulators that balance salt and water.
Doctors usually tailor treatments for hyponatremia in the elderly to their clinical situation, states Kugler and Hustead. For example, in severe hyponatremia, doctors may slowly raise the serum sodium concentration in the patient's body in a 24-hour period, while in acute hyponatremia, they administer hypotonic solutions.