INTRODUCTION: Hyponatremia is the most common electrolyte disorder detected by bio-chemical laboratories in the present time and interest about it increases because of new informations about its consequences. AIM: Objective of our work was to determine the prevalence of hyponatremia in patients hospitalized at clinic of internal medicine and to analyze its most common causes. PATIENTS AND RESULTS: The total number of hospitalized patients for a period of 6 months was 1,203. Severe hyponatremia, i.e. S Na < 130 mmol/ l was detected in 83 cases, i.e. 6.9% of all patients. 14 patients, i.e. 1.15% have more severe hyponatremia with S Na < 120 mmol/ l. The most common type of hyponatremia was hypervolemic hyponatremia (n = 41; 49.4%) associated with liver cirrhosis and hearth failure, less common was euvolemic hyponatremia (n = 28; 33.7%) and least common was hypovolemic hyponatremia (n = 14; 16.9%). The most common cause of euvolemic hyponatremia was syndrome of inappropriate antidiuretic hormone secretion (SIADH) and thiazide diure-tics therapy. Next to thiazide diuretics, other common cause of euvolemic hyponatremia, and so SIADH, was therapy by selective serotonin reuptake inhibitors (SSRI). CONCLUSION: The authors point out, that it is necessary to control serum sodium concentration on regular base in case of longterm therapy by thiazide diuretics or SSRI, especially in elderly patients.
INTRODUCTION:Hyponatremia is the most common electrolyte disorder detected by bio-chemical laboratories in the present time and interest about it increases because of new informations about its consequences. AIM: Objective of our work was to determine the prevalence of hyponatremia in patients hospitalized at clinic of internal medicine and to analyze its most common causes. PATIENTS AND RESULTS: The total number of hospitalized patients for a period of 6 months was 1,203. Severe hyponatremia, i.e. S Na < 130 mmol/ l was detected in 83 cases, i.e. 6.9% of all patients. 14 patients, i.e. 1.15% have more severe hyponatremia with S Na < 120 mmol/ l. The most common type of hyponatremia was hypervolemic hyponatremia (n = 41; 49.4%) associated with liver cirrhosis and hearth failure, less common was euvolemic hyponatremia (n = 28; 33.7%) and least common was hypovolemic hyponatremia (n = 14; 16.9%). The most common cause of euvolemic hyponatremia was syndrome of inappropriate antidiuretic hormone secretion (SIADH) and thiazide diure-tics therapy. Next to thiazide diuretics, other common cause of euvolemic hyponatremia, and so SIADH, was therapy by selective serotonin reuptake inhibitors (SSRI). CONCLUSION: The authors point out, that it is necessary to control serum sodium concentration on regular base in case of longterm therapy by thiazide diuretics or SSRI, especially in elderly patients.