How hypertension is classified and graded

Hypertension can be divided into primary hypertension and secondary hypertension according to the cause; according to the systolic and diastolic blood pressure values of blood pressure can be divided into three levels, systolic blood pressure between 140 and 159mmHg, diastolic blood pressure between 90 and 99mmHg belongs to hypertension level 1; systolic blood pressure belongs to hypertension level 3.