Fluid Balance in Hyponatremia

A 68-year-old patient with a history of heart failure presents to the emergency department with signs of edema, confusion, and shortness of breath. Upon assessment, the nurse notes that the patient's blood pressure is 90/60 mmHg, heart rate is 110 beats per minute, and the patient has crackles in the lungs upon auscultation.

The healthcare provider orders lab tests which indicate sodium levels of 130 mEq/L, indicating hyponatremia. The nurse knows that for every 1 mEq/L decrease in sodium concentration in an adult, the total body water increases by a factor of ________.