High urine output can be caused by excessive water intake, drug factors, mental factors, endocrine metabolic disorders, kidney diseases and many other reasons. 1. Excessive water intake: excessive water intake or intake of high water content foods such as watermelon may cause temporary increase in urine output. 2. Drug factors: such as hydrochlorothiazide, furosemide and other diuretics, patients may also experience increased urine output after taking the drug. 3. Mental factors: such as mental tension, anxiety, fear, etc., can also promote urination, resulting in more urine. 4. Endocrine metabolic disorders: such as pituitary uremia, diabetes mellitus, hyperparathyroidism, primary aldosteronism, etc., may lead to increased urine output. 5. Kidney diseases: such as chronic nephritis, chronic pyelonephritis, renal tubular acidosis, etc., the patient may also be accompanied by proteinuria, hematuria, hypertension, lumbar and knee pain and other symptoms. To summarize, patients with symptoms of excessive urination, persistent unrelieved or accompanied by other discomforts, should consult a doctor in a timely manner, under the guidance of the doctor to identify the cause of the disease, and if necessary, to carry out the appropriate treatment.