男,55岁。因反复头昏、头晕3年,加剧4天,于1991年3月19日入院。诊断为原发性高血压病Ⅱ期。于入院当日予硝苯吡啶10mg口服,一日3次。当日尿量剧增,24小时总量达7000ml(白天尿量4500ml,夜尿2500ml),排尿次数明显增多;当日气温8～10℃,患者24小时水摄入量约1000ml。遂停药,次日尿量即恢复正常。于3天 Male, 55 years old. Due to repeated dizziness, dizziness 3 years, aggravating 4 days, March 19, 1991 admission. Diagnosis of essential hypertension Ⅱ period. On the day of admission to nifedipine 10mg orally, three times a day. On the same day, the urine output increased sharply, with a total amount of 7000ml in 24 hours (daytime urine output 4500ml and nocturnal urine 2500ml). The number of urination increased obviously. On the day the temperature was 8 ~ 10 ℃, the patient’s water intake for 24 hours was about 1000ml. Then stop taking the urine the next day that is back to normal. In 3 days