WHAT IS HYPERTENSION?
Hypertension is derived from two root words; Hyper meaning High and Tension meaning Pressure. Hypertension simply means high blood pressure. Pressure is the force generated when the heart contracts and pump blood through the blood vessels that conduct the blood to various parts of the blood.
Although hypertension does not mean or result from excessive emotional tension, but evidence shows that stress and emotional tension do cause increase in blood pressure, and if continuous, could be sustained.
High blood pressure is therefore generally defined as a blood pressure exceeding 140/90mmHg confirmed on multiple occasions. The top number (140) is called the SYSTOLIC PRESSURE, and it represents the pressure in the blood vessels (arteries) as the heart contracts and pump blood into circulation. The bottom number (90) is called DIASTOLIC PRESSURE, and it represents the pressure in the blood vessels as the heart relaxes after contraction. These figures measured in millimeters of Mercury (mmHg) reflect the highest and lowest pressures the heart and blood vessels are exposed to during circulation. The generally accepted normal value for blood pressure is 120/80mmHg. Above this value but less than 140/90mmHg is not considered to be hypertensive yet but signals danger, it is therefore called High normal.
An elevation of the blood pressure (Hypertension) increases the risk of developing Heart (Cardiac) diseases such as Heart Failure and Heart attack, Kidney diseases, Vascular diseases like athelosclerosis (hardening and narrowing of blood vessels), Eye damage and Stroke (brain damage).
These complications called End organ damage arise as a result of long standing (chronic) hypertension. But victims of hypertension are not aware, at an early stage, that they have the disease, until these complications start appearing. This is because hypertension shows virtually no signs/symptoms at the early stage. For this reason, it is generally referred to as the ‘Silent Killer’.
The damage caused by hypertension increases in severity as the blood pressure increases. Based on this hypertension can be classified as follows:
CATEGORY SYSTOLIC(mmHg) DIASTOLIC(mmHg)
Normal Less than 130 Less than 85
High Normal 130 – 139 85 – 89
Mild Hypertension 140 – 159 90 – 99
Moderate Hypertension 160 – 179 100 – 109
Severe Hypertension 180 – 209 110 – 119
Very Severe Hypertension Greater than 210 Greater than 120
BORDERLINE HYPERTENSION.
Borderline Hypertension is defined as mildly elevated blood pressure that is found to be higher than 140/90mmHg at some times and lower than that at other times.
Patients with borderline value need to have their blood pressure monitored more frequently. They also need to assess end organ damage to be aware of the significance of their hypertension.
It should, however, be emphasized that patients with borderline hypertension have a higher tendency to develop a more sustained hypertension as they get older. They stand a modest risk of having heart related diseases. A close monitoring of their blood pressure and lifestyles could be very useful in this regard.
WHITE COAT HYPERTENSION
A single elevated blood pressure reading in the doctor’s office could be misleading, because the elevation might only be temporary. Evidence over the years has shown that anxiety related to the stress of the examination and fear of the result often result in blood pressure elevation noticed in the doctor’s office only. Infact, it has been suggested that one out of every four persons thought to have mild hypertension, actually may have normal blood pressure outside the physician’s office. This sort of elevated blood pressure noticed in the physician’s office is called ‘White Coat Hypertension’. Suggesting that the white coat, symbolic of the physician, induces the patient’s anxiety and a passing increase in blood pressure. Accordingly, monitoring of blood pressure at home, when in a more relaxed state of mind, can provide a more reliable estimate of the frequency and/or consistency of blood pressure changes.
WHAT CAUSES HYPERTENSION?
The Blood pressure is determined by two major parameters; Cardiac output i.e. the volume of blood pumped by the heart, and the Total peripheral resistance i.e. the resistance of the blood vessels through which blood flows. Hypertension is therefore an end result of either increased force of pumping by the heart, or constriction/narrowing of blood vessels causing increased resistance to blood flow or both.
Using the cause of hypertension as a yardstick, two major types of hypertension can be described;
Essential Hypertension
Secondary hypertension
The former also called Primary or Idiopathic hypertension is by far the most prevalent type of hypertension. It accounts for over 90% of all hypertension cases. No clear cut cause(s) can be identified for this type of accommodation, hence the name Idiopathic.
The later accounts for less than 10% of all cases. In this case, the hypertension is secondary to an existing abnormality in one or more systems or organs of the body. The most common causes are related to kidney and hormonal problems. The persistent uncontrolled use of contraceptives, especially in females over 35years of age fall under hormonal causes of hypertension.
Since no clear-cut cause(s) can be adduce for the most common types of hypertension, as with the case with most non-communicable diseases, we therefore talk in terms of ‘Risk Factors’ and not causes. These Risk Factors are actions/inactions that increases chances of getting a disease. Several researches over the years have shown that some factors are directly or indirectly related to the occurrence of hypertension. Some of the factors include:
HEREDITARY: High blood pressure tends to run in some families and races. It is believed that some inherited traits predispose some people to hypertension. For example, high blood pressure tends to be more prevalent in blacks than whites.
A family history of hypertension increases one chances of high blood pressure. Regular monitoring of blood pressure becomes very vital.
HIGH SALT INTAKE: High intake of Sodium Chloride (table salt) has being linked to high blood pressure. The condition develops mostly in societies or communities that have a fairly high intake of salt, exceeding 5.8grams daily. In fact, salt intake may be a particularly important factor in relation to essential hypertension that is associated with advancing age, black racial background, hereditary susceptibility, obesity and kidney failure. Research has shown that:
a. Rise in blood pressure with age is directly related to increase level of sat intake, especially in blacks.
b. People who consume little sodium chloride develop no high blood pressure when they consume more, hypertension appears.
c. Increased Sodium is found in the blood vessels and blood of most hypertensives.
Cutting down on salt intake is therefore a reasonable step in preventing hypertension
OBESITY: