Question
What are the treatment methods for excessive urination in children?
Answer
Excessive urination can be categorized into two main types based on its pathophysiology: (1) Hypertonic polyuria: Urine specific gravity is above 1.020, and urine osmolality is significantly higher than plasma osmolality. This can be caused by excessive glucose excretion (diabetes), excessive urea excretion (high-protein diet, high-calorie nasogastric feeding), or excessive urinary sodium excretion (chronic adrenal cortical insufficiency). (2) Hypotonic polyuria: Urine specific gravity is below 1.005, and urine osmolality is significantly lower than plasma osmolality. There are two types: polyuria insensitive to antidiuretic hormone and polyuria sensitive to antidiuretic hormone. The former is caused by renal lesions and is seen in various causes of chronic interstitial nephritis, hypokalemic nephropathy (primary hyperaldosteronism, chronic diarrhea, etc.), hypercalcemic nephropathy (hyperparathyroidism, etc.), hyperuricemia, syndrome of inappropriate antidiuretic hormone secretion, polycystic kidney disease, and renal diabetes insipidus; the latter is seen in diabetes insipidus and polyuria caused by excessive thirst and drinking. When making a differential diagnosis, start from the following four points: ① First, differentiate between hypertonic or hypotonic polyuria by measuring urine specific gravity, urine osmolality, and plasma osmolality; ② For osmotic polyuria, measure fasting blood glucose, blood and urine sodium, blood and urine urea, etc., to determine the cause of hypertonic polyuria.