High Blood Pressure (Hypertension) Part One- Diagnosis

Hypertension is the persistent abnormal elevation of Blood Pressure. Daytime Blood Pressure should be below 140/90.  Hypertension has nothing to do with “tension” and  is not a diagnosis of being highly tense or “stressed”. The cause of hypertension is unknown in most cases, although in some it can be due to kidney disease or hormonal problems. We do know  that it tends to run in families and there is a strong genetic tendency for the BP to be raised.

 Diagnosing high Blood Pressure is not as straight forward as taking an isolated reading in the surgery.  Blood Pressure normally fluctuates during the day, going up during exercise, and in such situations as extreme emotion or fear,traffic, disputes or sex. It falls when you sleep and are at rest.  Hypertension was previously diagnosed on the basis of 3 or more consecutive elevated readings over a period of weeks to months. Now there is a greater tendency to use a 24 Hr BP monitor which measures BP every 30mins over a 24Hr period. These devices are generally small and not intrusive, but be aware that you cannot shower or bathe for 24hrs while wearing the device.  The results give averages for day, night and for the entire 24hrs, as well as producing a chart demonstrating how much of the time it is acceptable.  The night-time readings should be lower,  being less than 120/70, the day readings less than 140/90 and the 24 hr average less than 135/85.

Once BP lowering medication is initiated, it is for the rest of your life, not without side-effects and not inexpensive.  It is therefore worth the effort to have a 24 Hr BP monitor performed before making the lifelong commitment to pharmacological treatment.

Other tests which should be considered include an Elecrocardiogram or ECG (EKG in many countries) to ascertain whether there is evidence of thickening of the wall of the left ventricle(the main pumping chamber), tests for kidney function including serum urea, creatinine and electrolytes, and urine testing for blood, protein and sugar. Kidney disease is an uncommon cause of elevated BP, but very important to detect in order to preserve kidney function.  Blood tests of liver function are also usually ordered as a baseline to check that the liver is functioning normally and capable of metabolizing any medication which may be needed, and the usual battery of blood tests includes a blood cell count, ESR(which is a risk factor for heart disease); fasting glucose to test for diabetes and fasting cholesterol, triglycerides and lipid profile-all checking for  other risk factors for heart disease.

At this point you are leaving the doctor’s office somewhat overwhelmed that you may have “Hypertension” and with  forms to have a 24 Hr BP monitor, blood tests and a heart trace. You cannot help but wonder “Why all the fuss about blood pressure anyway…is it all that bad? Actually I feel pretty good.”. Truth is, many studies have shown that a persistent elevation of  BP above 140/90 is linked to an increase in Heart Attacks and Strokes. Many studies also exist which show that treatment to bring the BP down to the normal range of under 135/85 brings about a reduction in mortality from Strokes in particular and heart attacks.  Now you have an appointment for 2 weeks time, but the suspense is getting to you, so you purchase a home BP monitor from the local pharmacy.  You decide that you won’t mention that to the doctor as you aren’t sure what the doctor’s reaction will be.  Well from this doctor, I am in favour of it.  Patients with their own BP machines tend to keep a better watch over their BP and generally their readings are better.

Part 2 will focus on Treatment of Hypertension