A week ago, I met an elderly woman who was referred from the XW hospital and asked what was wrong with her lately. She replied that she was fine, but she was urinating too much at night, 4-5 times a night, with a lot of volume each time. This surprised me, because elderly men mostly suffer from prostate enlargement and often urinate frequently, even 4-5 times per night. The frequency of urination in old ladies is mostly seen in urinary tract infections, but it is often accompanied by symptoms of urinary urgency and painful infection. But this old man had no other symptoms. The old lady has been taking medication for coronary heart disease and hypertension for many years, and her condition is well controlled. However, in the past year, she had leg swelling, which was usually severe in the afternoon and evening, and reduced the next morning after sleeping. The liver and kidney functions were normal, and the ultrasound of the lower extremities reported venous regurgitation of the lower extremities. So I started to take diuretic and anti-swelling drugs: furosemide + spironolactone combination, 1 tablet each per day. Since, the leg swelling was obvious at night, the elderly felt that the decongestants should be taken when the symptoms were most severe. So, every night before going to bed, he took these two anti-swelling drugs. The swollen legs improved, but since then the old man had to get up 4-5 times a night to urinate, which seriously affected his rest. After careful questioning of the drugs taken by the elderly, it was found that one of the antihypertensive drugs was nifedipine controlled-release tablets. Combining the time of taking the medication and the time of symptoms, I concluded that this elderly woman’s lower limb edema was a side effect of nifedipine controlled-release tablets. So I switched to Irbesartan Hydrochlorothiazide Tablets, an antihypertensive drug, and took it every morning. At the time of the follow-up visit, the swelling in her legs had subsided and, more importantly, her nighttime urination had decreased significantly and her nighttime sleep was much improved. Diuretics and decongestants are a very common class of therapeutic drugs, often used for heart failure, hypertension, renal failure, edema, etc. The most commonly used drugs are furosemide (Furosemide), which is a diuretic. The most commonly used ones are furosemide (tachyphylaxis), hydrochlorothiazide, spironolactone (ambien), and aminoglutethimide. The first two are potassium-removing diuretics and the last two are potassium-preserving diuretics. Generally, the combination of potassium-removing diuretics and potassium-preserving diuretics is chosen when taking medication to prevent low blood potassium and high blood potassium. In addition, excessive or prolonged use of diuretics can cause other electrolyte disorders such as hyponatremia, hypochlorhydria, hypomagnesemia and acid-base imbalance. It can also cause elevated blood uric acid and even disorders of lipid and blood glucose metabolism. Therefore, they should be used intermittently. In addition, diuretics have hypotensive effects, so care should also be taken to prevent hypotension when using diuretics. Of course, diuretics are usually taken in the morning to prevent excessive nighttime urination from affecting sleep and rest.