Diuretics are often prescribed to treat high blood pressure. given the name of the class of drug, how do diuretics affect the kidney, the fluid and electrolyte balance in the body, and the overall blood pressure?

Diuretics incease the urine flow within the excretory system. 

The kidney which is responsible for the process of filtering toxins and other harmful chemicals within the cells produce urine as a form of product which is the combination of all the harmful chemicals.