The diagnostic criteria for hypertension are a systolic blood pressure ≥ 140 mmHg or a diastolic blood pressure ≥ 90 mmHg. 140-90 mmHg systolic and 90-60 mmHg diastolic are normal blood pressure ranges, and 120/80 mmHg is a more desirable blood pressure. Diagnosis of hypertensive disease also has to be specifically graded, when the systolic blood pressure ≥ 140mmHg or diastolic blood pressure ≥ 90mmHg, is hypertensive disease grade 1. When the systolic blood pressure is ≥ 160 mmHg or diastolic blood pressure is ≥ 100 mmHg, it is grade 2 hypertension. When the systolic blood pressure is ≥180mmHg or diastolic blood pressure is ≥110mmHg, it is hypertension grade 3.