According to WebMD, blood pressure in the normal range is classified as 120 over 80. The top number is the systolic and the bottom number is diastolic.
Having high blood pressure is called hypertension, and the prehypertension levels are 120 to 139 over 80 to 89, notes WebMD. Stage one high blood pressure ranges from 140 to 159 over 90 to 99 and stage 2 high blood pressure is 160 plus over 100 plus. High blood pressure for those over the age of 60 is 150 plus over 90 plus. People who have blood pressure in the prehypertension and above ranges should seek the advice of their doctor to take steps to lower it.