Blood pressure and hypertension

High blood pressure (HBP) is known as hypertension. Blood pressure (BP) is a measure of the tension (force) within the arteries (blood vessels). BP depends on several factors such as the force of contraction of the heart muscle, the amount of blood pushed out of the left side of the heart, and the degree of resistance of the large , medium and small blood vessels to the flow of blood; this last factor is called the peripheral resistance. When the heart muscles contract (this is called systole) the pressure rises; in between contractions (i.e. during diastole) the pressure gets less. BP is measured with an instrument called the sphygmomanometer (BP apparatus). It is important to record the BP in resting conditions over a period of time: more than one measurement should be taken lt is also necessary to take measurements with the person lying down, seated and standing; this is because posture influences the BP which tends to fall on standing. There are other more sophisticated types of apparatus, such as digital and electronic instruments. The reading is in millimeters of mercury. There are two measurements of BP: systolic BP, mainly due to the contraction of the heart, diastolic BP mainly due to the peripheral resistance. In adults, the usual systolic BP is around 120, and it may rise to about 140 in older people; the diastolic BP is around 80; in children it is less. If the systolic BP is over 140 or if the diastolic BP is over 90, treatment becomes necessary. When a person is tense or excited, the arterioles become constricted, and this causes an increase in the BP. In the majority of cases the exact cause of HBP is not known, and it is then referred to as primary or essential hypertension. 

Causes of hypertension

Factors known to cause HBP include kidney disease, some disorders of adrenal glands that produce hormones, abnormalities of large blood vessels (such as the aorta and main renal arteries), complication of diabetes, side effect of drugs such as prednisolone and drugs used for certain types of arthritis, excessive salt intake and stress and strain(emotional factors) are linked to HBP.

When a specific cause is identified it is called secondary hypertension. ln either of these categories, the HBP may either take a benign (not serious) course, or a malignant (serious) course. The benign form if untreated for several years can lead to the malignantform. ln mild cases symptoms may include headache, giddiness and shortness of breath. However, it is very important to remember that quite often HBP does not cause any symptoms. Therefore it may not be detected until complications arise. Some patients mav have severe early morning headache at the back of the head and chest pain. Due to persistent HBP resulting from the absence of treatment or poor control of BP, serious complications may occur. These include enlargement of the heart, heart failure, heart attacks, kidney failure, strokes.

Treatment for hypertension

There are a variety of anti-hypertensive drugs available, which could very satisfactorily control even the highest BP; however, patient's compliance is very necessary. If there is a secondary cause for HBP, this cause should be attended to. Renal (kidney) failure is a known complication of HBP. While HBP can lead to kidney failure, all forms of kidney diseases may cause HBP, which will in turn damage the kidney further, leading to either acute or chronic kidney failure, in which case supportive treatment such as peritoneal dialysis, hemodialysis (cleaning of blood) or kidney transplant may be required. lt is advisable to get the blood pressure checked at least once a year if you are above forty years of age, even if you feel quite well.