This happens when a diseased heart cannot pump normally and water collects in body tissues. This condition is called congestive heart failure. Some diuretics are used to help treat high blood pressure. Others are sometimes used to help treat glaucoma, a condition in which there is increased fluid pressure in the eye that can cause blindness. The mineral potassium, along with sodium and calcium, help regulate heart rhythm and several other important body functions.
Most diuretics cause the kidney to excrete potassium and sodium in the urine flow.
Diuretics increase the urine flow and therefore may increase the amount of potassium excreted. If your potassium level gets too low it can make you feel weak and cause your heart to beat irregularly. Your doctor will usually be able to help you avoid this problem by testing your blood for potassium or by asking you to increase your intake of potassium. Potassium is abundant in leafy vegetables, fruit and vegetable juices, bananas, and decaffeinated coffee powders. Sometimes your doctor will prescribe extra potassium in pill form.