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HYPERTENSION: chronically elevated blood pressure. In current usage, the word hypertension without a qualifier normally refers to systemic, arterial hypertension
Normal blood pressure: generally less than 120/80 mmHg (i.e. systolic blood
pressure less than 120 and diastolic blood pressure less than 80 mmHg).
Normal to high blood pressure: between 120/80 and 140/90 mmHg.
High blood pressure: 140/90 mmHg or higher. If your blood pressure is
180/110 mmHg or higher, you have very high blood pressure.

Essential/Primary Hypertension: no specific medical cause can be found to explain the rasied pressure.
Secondary Hypertension: the high blood pressure is a result of (i.e., secondary to) another condition.


Worldwide: estimated 600 million people affected worldwide (Cardiovascular Diseases – Prevention and Control, WHO, 2001-2002)
Australia: hypertension reported by 11% (2.1 million) (National Heart Foundation)
Indigenous Australia: unknown

Investigations to diagnose primary/secondary hypertension and the effects on the body of hypertension.

Primary hypertension is when there is no underlying cause and instead it is due to a mix of behavioral, hereditary and other factors. It accounts for ~90%. Things like being overweight, having a diet high in cholesterol and saturated fat, smoking, race, hereditary and gender all contribute to having primary hypertension. Secondary is due to an underlying cause such as kidney disease, Cushings syndrome and polycythemia.

The investigations;
To diagnose hypertension you must get a high reading 3 times, spaced about a week apart. Make sure that the BP was not taken within 30mins of caffeine, after a cigarette, when the person is stressed or has any other outside influences that would increase the BP eg. White coat hypertension (try an at home monitor).

You would then do investigations to rule out a secondary hypertension. You’d also do tests to look for the extent of damage already caused by the hypertension.
These include:
- blood tests for
o creatinine – for kidney disease
o glucose – for diabetes
o electrolytes – sodium and potassium
o cholesterol
- urine test for
o proteinuria – for kidney disease
- an ECG – for heart damage
- a chest xray. – for heart enlargement

If none of these come back positive and you can’t find any other underlying causes then start looking at the risk factors for primary hypertension. There are treatments both with behavioral changes and drug therapies for primary hypertension.

If hypertension is left untreated:
- is the major cause of heart and kidney failure and stroke
- Causes heart damage because of an increased afterload which makes the ventricles work harder to expel the blood. This causes hypertrophy but eventually overstretches and becomes less efficient.
- Strains the blood vessels and tears the endothelium which creates focal points for atherosclerosis
- Atherosclerosis then worsens the hypertension with the positive feedback cycle
- The kidneys are damaged, their arterioles thicken with the stress which decreases the renal blood flow. When the kidneys detect a drop in BP they release ‘renin’ which leads to formation of the vasoconstrictor angiotensin 2 and aldosterone (hormone) which promotes salt retention. These effects then worsen the hypertension again.
- If the diastolic exceeds 120mmHg = blood vessels in eyes hemorrhage, blindness, kidneys and heart rapidly deteriorate and you die within 2 years

Usefulness of home blood pressure meters for a GP (i.e. monitoring over longer term)
• White Coat Hypertension – phenomenon where patients exhibit raised blood pressure in a clinical setting but not otherwise. Is often associated with anxiety.
• Ambulatory Blood Pressure Monitoring (ABPM): a device measures blood pressure at regular intervals throughout the day and night. (Thus reducing white coat hypertension errors).
• Home monitoring may also help to improve hypertension management and to monitor hypertension management such as the effects of lifestyle changes and medication related to blood pressure. Compared to ambulatory pressure measurements, home monitoring has been found to be an effective and lower cost alternative.
• Other Advantages:
o May encourage patients to participate more actively in their own treatment
o Improve adherence to antihypertensive drug therapy
o Aid doctors in evaluating the efficacy of treatment and in simplifying medication regimens
o Prevent the need for frequent office visits
• Disadvantages:
o Many commercially available devices are inaccurate
o Not everyone is able to obtain satisfactory readings
o Most patients require training (and because doctors generally only have a peripheral role in the selection and use of these devices, it is doubtful that most patients receive adequate training.
o The self-measured readings may not be representative of the patient’s usual blood pressure as the measurements are usually taken when convenient. Thus, at home during the morning or night, but not generally during the day or at work.
Precautions to take before taking a self blood pressure measurement:
1. Empty your bladder before sitting down to take a reading.
2. Don’t drink coffee for at least an hour before measuring your blood pressure.
3. Don’t smoke for at least 1 hour before.
4. Sit for five minutes with your back supported and your feet flat on the ground before taking your blood pressure. Keep your arm supported on a table at heart height.
5. Do not wear tight fitting clothes on your arm. When you fit the cuff, your rolled up sleeve should not be constricting your arm at all. If in doubt, take off your top.
6. Take two readings two minutes apart, and find the average.

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