Some people take a thiazide diuretic in the morning and furosemide after getting home in the afternoon. If you forget to take your diuretic for a day or two, you may have a quick build-up of fluid. This may lead to acute shortness of breath at night. That can cause much fear for you and your family. However, only your doctor should make any changes in your treatment.
Diuretics can cause changes in levels of other salts and substances in the blood.
Sometimes your doctor may need to have your blood tested to make sure that the levels are staying normal. The blood tests may be needed if you have passed a very large amount of urine in a short time or if the diuretic treatment does not seem to work. The most useful effect is to reduce the work of the heart by opening up blood vessels. That leads to a lower blood pressure. These drugs have been shown to lengthen life.