Patient's question:
Hello, the situation you mentioned should not exist, because his personality seems very cheerful and playful, always smiling, and each time his urine output is not reduced, and his sleep is very normal, but even when sleeping, he needs to get up 5-8 times every night, and usually naps for about two hours in the afternoon, but he also needs to get up to urinate several times, but he drinks a lot. Please analyze it for me again, what is the actual reason. What should he eat?Doctor's answer:
Hello, according to the pathological and physiological classification of polyuria, it can be divided into two major categories:(1) Hypertonic polyuria: Urine specific gravity is above 1.020, and urine osmolarity significantly exceeds plasma osmolarity. It can be caused by excessive glucose excretion (diabetes), excessive urea excretion (high-protein diet, high-calorie enteral nutrition), or excessive sodium excretion (chronic adrenal cortical insufficiency).
(2) Hypotonic polyuria: Urine specific gravity is below 1.005, and urine osmolarity significantly plasma osmolarity. It is further divided into two types: vasopressin-insensitive polyuria and vasopressin-sensitive polyuria. The former is caused by renal lesions and is seen in various conditions such as chronic interstitial nephritis (due to various causes), hypokalemic nephropathy (e.g., primary aldosteronism, chronic diarrhea), hypercalcemic nephropathy (e.g., hyperparathyroidism), hyperuricemia, Sj?gren's syndrome, polycystic kidney disease, and nephrogenic diabetes insipidus. The latter is seen in diabetes insipidus and polyuria caused by excessive thirst and drinking.
For differential diagnosis, the following four points should be considered:
① First, distinguish between hypertonic or hypotonic polyuria by measuring urine specific gravity, urine osmolarity, and plasma osmolarity.
② For osmotic polyuria, measure fasting blood glucose, blood and urine sodium, blood and urine urea, etc., to determine the type of solute causing the hypertonic diuresis. Based on medical history and a detailed physical examination, the etiology can be identified.
③ For hypotonic polyuria, water deprivation tests, hypertonic saline tests, and vasopressin tests can be performed to clarify whether the polyuria is renal, psychiatric, or central in origin.
④ For renal polyuria, medical history, physical examination, and laboratory tests such as renal function, serum potassium, serum calcium, and serum uric acid can be used to further determine the etiology.