Hypertension &  Prevention Blood pressure is the force of blood against the artery walls. It is expressed as systolic and diastolic pressures. Both numbers must be maintained within normal values. Normal reading=120/80mmhg(+or-10) Chronic elevation in bp (systolic ≥140 mmHg or diastolic ≥90 mmHg is called Hypertension  Causes of hypertension Stress Depression Anxiety disorder Mood disorder