Each time the heart muscle contracts it pumps blood into the arteries that carry oxygen-rich blood to the tissues of the body. Blood pressure is a measure of pressure in the arteries. This may be compared to the pressure of water in a garden hose, except that the arterial wall is a living tissue.
High blood pressure, or hypertension is considered to exist when the pressure in the arteries exceeds a certain threshold.
Blood pressure is recorded as two numbers, e.g. 125/80 mmHg (millimeters of mercury; a measure of pressure). The higher number is the systolic pressure, that is when the heart muscle contracts and blood is pumped into the blood vessels. The lower figure, the diastolic pressure, is the pressure when the heart is relaxing and filling up with blood, between strokes.
What is hypertension?
Hypertension is considered to exist when systolic blood pressure is above 140 mmHg and/or diastolic blood pressure is above 90 mm Hg.
Remember that blood pressure varies quite much from time to time.Therefore, repeated measurements are necessary to decide if high blood pressure is present or not.
Hypertension often causes no discomfort. You can therefore have high blood pressure without knowing it. Therefore, it is important to have blood pressure measured regularly, preferably once a year.
Hypertension is an undesirable situation because it increases the risk of stroke, heart attack, heart failure and kidney disease.
What causes hypertension?
Hypertension is a complex disorder and despite years of research a simple underlying cause of high blood pressure has not been found. Family history plays a big role and some important risk factors have been defined. In rare cases, an underlying cause is found such as a narrowing of a renal artery, disorders of the adrenal or thyroid glands. More commonly, however, no underlying cause is found. This is called a essential hypertension and is a very common disorder.
Although blood pressure measurement are relatively easy to perform, blood pressure varies a lot. This can make it difficult to define whether hypertension is present or not. Some individuals have elevated blood pressure in certain conditions, such as in the doctors office, sometimes called “white coat hypertension.” It is often necessary to make repeated measurements to detect hypertension and it is not justifiable to start treatment unless hypertension has been well documented. It may be very helpful if you measure blood pressure self at home. It is important to record all measurements. Repeated automatic measurements for 24 hours may be very helpful, a special equipment is needed for this procedure. Do not hesitate to seek medical attention if you suspect hypertension.
What to do?
The following factors increase the risk of hypertension: Overweight,obesity, lack of exercise, excessive alcohol consumption, excessive consumption of fat or salt-rich foods and smoking. Pregnancy and contraceptive pills increase the risk of hypertension in women.
If you want to reduce the risk of high blood pressure, avoid overweight and obesity. Do not consume much fat or salty meals, avoid licorice and exercise regularly. Don’t smoke and drink alcohol in moderation.
The DASH diet
Studies have shown quite conclusively that the DASH (Dietary Approach to Stop Hypertension) diet lowers blood pressure and has many other beneficial effects on health. The DASH study was published in 1997 and received much attention. The study showed that this diet lowered blood pressure in subjects with high or borderline high blood pressure. Other studies have shown that the DASH diet has beneficial effects on obesity and is likely to reduce the incidence of diabetes, heart disease, some cancers and kidney stone formation.
The DASH diet recommends consumption of fruits and vegetables, whole grain products, low fat dairy products, fish, poultry and food rich amounts of in magnesium, calcium and potassium. Reduce the consumption of fat, especially saturated fat, cholesterol, red meat and sweets.
In many cases, sufficient changes in lifestyle will not to lower blood pressure enough. In these situations you will probably need drug treatment. There are a number of drugs available that lower blood pressure. The main drug classes are so called thiazide diuretics, ACE inhibitors, calcium channel blockers, ARB drugs (angiotensin receptor blockers), and beta blockers. Sometimes treatment with more than one drug is necessary. A number of clinical trials have shown that treatment with these drugs lowers blood pressure and lessens the risk of stroke, heart attack, kidney disease and heart failure.