Grading of Hyponatremia

Hyponatremia is clinically classified into three severity grades: mild, moderate, and severe. Mild hyponatremia refers to a serum sodium concentration below 135 mmol/L; patients may experience dizziness, paresthesia (numbness or tingling) in the extremities, and fatigue. Moderate hyponatremia is defined as a serum sodium concentration below 130 mmol/L; affected individuals may develop nausea, vomiting, and hemodynamic instability (e.g., fluctuating blood pressure), along with symptoms such as dizziness and blurred vision. Severe hyponatremia denotes a serum sodium concentration below 120 mmol/L; patients may exhibit altered mental status, diminished or absent deep tendon reflexes. In severe cases, respiratory distress, coma, or hypovolemic shock may occur.