Health Tips - Blood Pressure

The blood pressure depends principally on the cardiac output and the peripheral resistance. The range of normal varies considerably not only with the circumference of the arm in relation to the width of the cuff. The blood pressure varies greatly with exercise and emotion, and to a slight extent with meals and smoking. Casual readings in the consulting room or out-patient department maybe very different from resting readings taken in bed after a night’s sleep, reassurance and repeated recordings on different occasions. The information to be gained from a single reading is limited. There is still some difference of opinion as to what level constitutes hypertension. A consistent level of 150/100 should be regarded as abnormal, but not necessarily of bad prognostic significance or requiring treatment.

It is important to distinguish predominantly systolic from diastolic hypertension. Emotion chiefly affects the systolic pressure. Systolic hypertension is also found in elderly patients with atherosclerosis of the aorta (and hence loss of elasticity) and in aortic incompetence, heart block and thyrotoxicosis. It is of farless significance in largely depends on constriction of the arterioles and is most commonly associated with essential hypertension, renal disease and toxaemia of pregnancy.

Pulse Pressure. The pulse pressure is the difference between the systolic and diastolic pressures. The normal range is 40-70mm. Hg. In hypertension the pulse pressure is commonly increased and particularly if there is atherosclerosis of the aorta as mentioned above. It is often raised in thyrotoxicosis, and in aortic incompetence it may be very high. In aortic stenosis it is characteristically low.