Even though potassium is essential for the human body, having too much of it can be dangerous and can cause severe damage to your heart, to the extent of causing cardiac arrest. However, there are a few ways to help quickly lower potassium levels in your blood.  Lowering down your potassium intake by taking low-potassium diet. Your doctor can recommend following a diet free of foods high in potassium to effectively lower potassium levels in your body. Some people may also require medication to reduce the potassium in their body and may need to continue the medicines to avoid further elevation of potassium. Water pills and potassium binders are two such medicines. Water pills work by increasing the urine production in your body and thus effectively removing excess potassium along with it. Potassium binders work by binding the extra potassium with your bowel.