HYPERTENSION – THE SILENT KILLER
Dr. Martin Akpan
Blood pressure (B.P) is the pressure existing against the inner walls of the large arteries (blood vessels) at the height of the pulse when the heart contracts (systole) and when the heart relaxes (diastole).
A normal blood pressure may vary as much as 40mmHg within 24 hours in the same person depending on the activity of the person. It rises with work and excitement such as at orgasm, on straining at stool and under stress. It falls during relaxation and sleep in the healthy normal person. A sustained rise above generally accepted levels for the age of the individual is what constitutes high blood pressure or hypertension.
Hypertension, therefore, according to the World Health Organization, WHO, expert committee, is a blood pressure level of or exceeding 160/95 mmHg. However, more often than not, a threshold criterion of 140/90 mmHg is used in practice. Studies from a cohort even indicate that BP bears a linear relationship with heart risk down to a systolic BP of 115mmHg. Hence it is suggested that 120-139/80-89mmHg be considered pre-hypertension and categorized as such rather than look at a single numerical threshold. Hypertension is a common medical problem in our society. Is has been described as a SILENT KILLER because it is a symptomless disease frequently discovered during routine examination of apparently healthy people. Most people with hypertension do not know they have it. Minor symptoms such as headache, dizziness, irritability fatigue and insomnia are sometimes experienced but these are not peculiar to hypertension.
Oftentimes diagnosis is made retrospectively as the unsuspecting patient suddenly presents in the hospital with one or more complications such as cerebrovascular accident (stroke) which the laity is wont to attribute to a spell from evil forces. Stroke is a sudden and dramatic outcome of uncontrolled hypertension. It is the climax (or is it anticlimax?) of a severe rise in the blood pressure resulting in the rupture of a cerebral vessel and spillage of blood on the brain cells. The resultant clinical picture is characterized usually by paralysis of one side of the body (hemiplegia). Or other neurological deficiencies and disabilities include epileptic fits, loss of visual and speech functions and even urinary impairment. Sometimes, disorientation, loss of consciousness and sudden death occur. It is therefore not uncommon to hear people discuss in subdued tones: “Ekpo amia enye”, meaning the person has been struck by an infernal being apparently sent from the enemy camp.
Another common complication of hypertension is heart failure, which features include tiredness, breathlessness and swelling of the feet among others. A heart failure patient with swollen legs is usually described in uncomplimentary terms in our communities as a victim of “mbiam”, a traditional concoction used to invoke the wrath of local deities and ancestral spirits on their offenders. It is important to emphasize that the real offender here is the heart failure, resulting from hypertension and not the poor innocent patient. Hypertension may become malignant with irreversible damages to the eyes and kidneys.
Hypertension is classified, according to its causes, in two major types: ESSENTIAL OR IDIOPATHIC hypertension and SECONDARY hypertension.
In about 80 to 90 percent of the patients, the cause of hypertension cannot be established. Those that belong to this group are said to have essential of idiopathic hypertension. Apart from stress which has been considered to be a causative factor, this type of hypertension which is particularly found among some races e.g. African-Americans and Japanese, is common where salt intake is excessive.
The remaining 10 to 20 percent of hypertensive patients belong to the SECONDARY group. Here definite causes can be found if painstaking investigations are carried out. Where the cause is found, cure is often possible. Some of the major causes of secondary hypertension include: coarctation (constriction) of the aorta, renal (kidney) diseases, endocrine disorders, hormone therapy e.g. oral contraception and pregnancy. Pregnancy can induce hypertension in a hitherto normotensive woman. It can also worsen a pre-existing hypertensive state. Other risk factors in hypertension include overweight, emotional stress, smoking, contraceptive pills and diets rich in saturated fats and salt.
Because of the heavy toll hypertension exacts on the human population, it is essential to enforce preventive measures. We can prevent hypertension or its devastating consequences by monitoring our blood pressure at four month intervals, developing a regular exercise programme, avoiding tobacco, cigarette smoking and alcohol. Besides, weight reduction dietary discipline and an effective stress and tension-handling technique are truly helpful and should be adopted. Pregnant women should undergo regular checks. Where a person has been identified as a hypertensive by a qualified medical doctor, and placed on antihypertensive regime, compliance and follow-up are a sine qua non to a successful control.