Chronic Hyponatremia: Causes, Symptoms, Diagnosis, Risks, and Management
Chronic hyponatremia is a medical condition in which the concentration of sodium in the blood falls below 135 mEq/L for 48 hours or longer. Sodium is one of the body’s most important electrolytes. It helps regulate fluid balance, nerve signaling, muscle contraction, and normal brain function. When sodium levels decline gradually over time, the body attempts to adapt, particularly within the brain. Although this adaptation reduces the immediate danger of brain swelling, chronic hyponatremia is far from harmless. For many years, chronic hyponatremia was often considered “mild” or “asymptomatic,” especially when sodium levels were only modestly reduced. Research now shows that even mild chronic reductions in sodium can significantly affect cognition, balance, bone health, and overall physical function. The condition is especially common among older adults, hospitalized patients, individuals taking certain medications, and people with chronic illnesses involving the heart, kidneys, liver,...