When you have hypertension the last thing you need is stress, which makes your blood pressure shoot right up. Unfortunately, when you are worried about your BP, having it checked by a doctor or nurse can be quite stressful. In fact, some people only have a high reading when their blood pressure is taken in the surgery, and have perfectly normal readings when it’s measured outside of the clinical environment. This is known as white coat hypertension.
What causes white coat hypertension?
White coat hypertension is due to stress. Stress causes your blood pressure to rise by triggering the production of adrenaline (epinephrine) hormone. This constricts your arteries and veins and makes your heart beat more quickly, so both your blood pressure and pulse rate increase. This is an adaptive response to supply your muscles and brain with more blood, oxygen and nutrients to help you fight or flee in dangerous situations. This effect is usually short-lived, so that if your doctor waits a few minutes and checks your blood pressure again, your blood pressure comes back down to normal as you feel more relaxed.
In people with white coat hypertension, however, the effects of stress are excessive and prolonged. White coat hypertension can increase systolic BP (the higher reading) by as much as 100 mm Hg, although this is extreme. More often, white coat hypertension increases systolic BP by 20-30 mmHg, and diastolic BP (the lower reading) by around 10 mmHg.
White coat hypertension is common
This phenomenon is more common than previously realised. Research published in the Journal of Hypertension assessed 163 people with mild to moderate hypertension whose blood pressure was checked in a clinic on eight separate occasions. An astonishing three out of four (75%) had substantial white coat hypertension on at least one occasion, in which their office BP reading was at least 20mmHg systolic (or 10mmHg diastolic) greater than blood pressure measurements obtained from home. One third consistently had substantial white coat hypertension on three or more occasions.
White coat hypertension is an important sign
Until recently, white coat hypertension was thought to be relatively harmless, but it is now recognised that over-sensitivity to stress can play havoc with your circulation. Not surprisingly, your arteries lose their responsiveness to natural regulation signals when they are subjected to a blood pressure that varies considerably, sometimes being high, sometimes low and sometimes normal.
In fact, latest research suggests that people with White Coat Hypertension have just as many abnormalities of the heart and blood vessels (such as stiffness and poor contraction of the left ventricle of the heart and decreased elasticity of artery walls) as those with persistently high blood pressure. They are also highly likely to develop severe hypertension in the future.
White coat hypertension is confirmed by wearing a 24-hour BP monitoring tape and recording stressful showing that BP rises in stressful conditions, including having BP measured by a doctor, then falls again in between.
If you are diagnosed as having white coat hypertension, it is important to monitor your blood pressure regularly yourself, at home, and to make diet and lifestyle changes to both improve your blood pressure control and improve your ability to cope with stress through relaxation such as meditation and aromatherapy.
My book, Overcoming High Blood Pressure, provides 3 complementary programs – Gentle, Moderate and Full-Strength – to help bring your blood pressure down naturally.
Click here for advice on choosing a blood pressure monitor to use at home.
Image credits: s_photo/shutterstock; kurhan/shutterstock