High blood pressure is divided into primary and secondary hypertension, secondary hypertension occurs in 10 % of patients and is due to other underlying diseases kidney diseases, hormonal disorders ... or medications , and is treated by treating the cause. primary hypertension is said to be idiopathic which means that it has no known cause , but many factors play a role in it including genetics, obesity , diabetes .... if you want more detailed information i advice you to have a look at the Health Information Center : http://google.com/coop/cse?cx=007185308018807068018%3Ax2z07lqx3mg which can give you more detailed explanation with scientific terms and so on .