Is it dangerous to stop taking a diuretic if you have congestive heart failure and high blood pressure and edema in legs?

Yes: Stopping diuretics may worsen heart failure, high blood pressure, leg swelling and cause fluid in your lungs. There may be a few indications to hold your diuretics. But always discuss with your physician first before making any medication changes.

Stop diuretic?: Why would one want to stop a diuretic with edema? The person in question should discuss the idea of stopping diuretics with the physician who ordered them and have the physician explain to that person why that is not a good idea. Apart from the fact that the edema will not resolve off diuretics, the person's BP will likely worsen off diuretic therapy.