High blood pressure or normally called as hypertension is not an disease or illness in itself but yes it can be considered as risk for development of other problems like strokes, heart attack and kidney disorder. High blood pressure is the condition which is prevailing among people worldwide and is the leading cause for morbidity and mortality. In United States about 1 in 3 adults is suffering from hypertension. Around 25% adults and over 5% of people below 18 years of age develop high blood pressure. Before jumping to our main topic i.e. hypertension, lets discuss about heart and other parameter which are vital in controlling blood pressure.
Mechanism of Blood transportation in Body
We all know that body is made up of billions of cells which are eventually grouped into tissues, organs and finally systems. The major organs which are involved in maintaining blood pressure are skin, heart, lungs, kidneys and some glands and including systems like circulatory and excretory systems. Blood is responsible for transporting materials throughout the body especially oxygen and foods to body cells in order to keep them alive and function normally and also carries waste product like carbon dioxide away from such cells and it is heart which facilitates pumping of blood throughout the body via an extensive network of arteries.
Heart is divided into two chambers i.e. left and right atria’s and ventricles and both the chambers of heart works in a synchronised manner. The basic route of transportation involves the movement of deoxygenated blood from veins into left ventricles which further pumps blood to the right atria, lung receives blood through pulmonary artery and purifies (oxygenate) the blood. This oxygenated blood returns back to the left atria, then to left ventricle and finally heart forcefully pumps out oxygenated blood from the left ventricle through the aorta which later divides to smaller arteries and then into capillaries. Since less amount of pressure is required to transport blood to lungs as compared to other parts of body, left part of heart is much larger, muscular and carries higher workload than right side of heart.
You can yourself understand that for transportation of bloods across body, heart does requires some amount of pressure, and this pressure with which heart pumps the blood out is termed as Blood Pressure (BP) or else we can define blood pressure as the force against which blood pushes against the walls of arteries. Also note that pressure in arteries is higher as compared to veins. The blood pressure is recorded in fractions like 120/80 which is considered as normal blood pressure and it is measured using instrument called sphygmomanometer. The upper number represents Systolic pressure which is the force generated when blood moves into the arteries and the bottom number denotes diastolic pressure which represents pressure in arteries when heart rests between beats i.e. when ventricle relaxes to fill blood into it for next push.
Blood pressure depends on various factors like viscosity of blood, elasticity and flexibility of arteries and veins, size, number, and state of arterioles. In certain circumstances like during exercise or emotional stress, heart pumps blood at faster rate but arteries may not be able to dilate enough to accommodate such large volume of blood. As a result the pressure increases on the walls of arteries and causes rupturing of a wall which leads to heart attack or stroke. Such a condition is termed as Hypertension or High Blood pressure. The term hypertension is derived from French word tension artevielle which means tension (stretching) of arterial walls. Hypertension develops when systolic pressure reaches up to 140mmHg or more and diastolic pressure in above 90 mmHg or more.
However our body consist of natural defense mechanism against high blood pressure.
- Pressure receptors that are present in various organs recognizes changes in blood pressure and then adjusts the pressure accordingly by altering force and speed of heart contraction.
- Renin-angiotensin system – The kidney plays very important role in regulating BP. The substance called renin is released from juxtaglomerular cells of kidneys. It is responsible for converting inactive angiotensinogen, released from lungs to active angiotensin l which is further converted to angiotensin II by angiotensin converting enzymes. The angiotensin II is potent vaso-active compound that causes increase in blood pressure. Renin test is usually conducted to determine cause of hypertension
- Aldosterone is released from adrenal glands in case of high potassium or angiotensin levels and decreases blood pressures by increasing excretion of potassium by kidney and also facilitating sodium absorption.
Signs of high blood pressure
High blood pressure is commonly referred to as “silent disease”, because it typically doesn’t announce itself with any remarkable signs and also it is not associated with any universal symptoms. It is possible that you may observe no signs of hypertension for years even if that disease is prevailing in your body. Hypertension doesn’t develop problems in short period of time. It usually takes several years to produce any noticeable symptoms. Thus, the best way to detect hypertension is through regular health check-ups.
The two major signs of high blood pressure are headache and breathlessness. Headache is most common sign of hypertension. The sub occipital pulsating headaches, usually in morning and subsiding during the day is characteristics feature of hypertension. It is believed that high blood pressure results in activation of phenomenon called as Auto regulation in the blood vessels which circulates within the tissues underneath the skulls and leads to constriction of blood vessels which is the major cause for headache. It has been observed that people with high blood pressure or with high pulse and systolic pressure have fewer chances of headache as compared to people with normal blood pressure. Thus we can say that headache risks increases with fall in blood pressure.
The breathing problems might be accompanied by increasing blood pressure. Sometimes due to high blood pressure, body may not be able to distribute enough oxygen to brain, muscles and thus sense of breathlessness may evolve. Also due to improper filling and emptying of chambers produces elevated pressure in blood vessels around lungs which produces difficulty in breathing specially when lying during night. It is observed that breathlessness and headache are observed when blood pressure reaches 180/120mmHg.
Other important signs of hypertension is Retinal changes like production of exudate, haemorrhage or papilledema (swelling of optic nerve). Others signs of hypertension includes nausea, chest pain, blood in urine, swelling of legs and feet’s, constipation, cough and vomiting.
In case if you observe any such signs of hypertension as mentioned above report immediately to physician and seeks for his advice and start proper treatment. The best way to high blood pressure under control is through exercise and change in diet and lifestyle.