Understanding Hyponatremia: Which Sodium Level is Low?
                                
                                
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                                    5 min read                                
                            
                                Studies show that between 15% and 20% of hospitalized patients experience low blood sodium, or hyponatremia. This condition is medically defined by answering the question: which sodium level is low? It occurs when blood sodium drops below 135 mEq/L.