When there is too much fluid in the blood the heart must pump harder. diuretics are substances that stimulate the kidneys to remove more fluid from the body. why do you think diuretics are often prescribed as a treatment for high blood pressure?

Diuretics are often prescribed for treating high blood pressure in order to prevent further vascular constriction and promote vascular dilation. This simply means that blood vessels are able to open properly to enable blood to flow easily within the body. When blood is flowing properly within the vascular system of the body, blood pressure will decrease. Diuretics have the ability to create vascular dilation hence it is part of protocol to be given to individuals who have high blood pressure. 

It hurts for them at first then they get used to it

Amos cookies- i have no idea