This observational study aims to analyze the time of correction of hyponatremia in patients within an internal medicine ward. The researchers will assess volume status using both clinical evaluation and point-of-care ultrasound. Patients will be categorized based on whether they have the same volume status determined clinically and by ultrasound or a different status between the two methods. By tracking sodium levels daily until normalization, the study will compare the time of hyponatremia correction between the two groups.

The main question it aims to answer are What is the time of correction of hyponatremia by assessing the volume status clinically or by point of care of ultrasound?.

Participants will be asked to participate in the study and they will be receive a volume status by a portable ultrasound. If they have the same volume status clinically and by point of care ultrasound they will be referred as group 1. If they have a different volume status clinically or by point of care ultrasound they will be referred as group 2.

Researchers will follow the patients by measuring the sodium levels daily until they reach normal sodium levels ( >135mEq/L) and will compare group 1 and group 2 with a survival analysis.

Inclusion Criteria:

• Age greater or equal to 18 years
• Hypotonic hyponatremia (less than 275mosm/kg) calculated by the following formula (2 Na+Glucose/ 18)

Exclusion Criteria:

• Patients who are critically ill with ventilatory support.
• Patients with clinical signs suggestive of hypovolemia and have a documented history of aortic insufficiency or show mitral insufficiency during POCUS (Point-of-Care Ultrasound).

Patients with hypotonic hyponatremia