Blood pressure is highest when the heart contracts and drives the blood into the arteries. This is called the systolic pressure. When the heart muscle is relaxing, no blood is being pushed from it and blood is leaving the arteries through the arterioles. At this time the blood pressure is lower (diastolic pressure). Systolic pressure gives valuable information about the force of the left ventricle contraction, ad diastolic pressure gives important information about the resistance of blood vessels. Clinically, diastolic pressure is considered more important than systolic pressure, because it indicates the pressure or strain to which blood vessels are constantly subjected. It also reflects the condition of the peripheral vessels, since diastolic pressure rises or falls with the peripheral resistance. If arteries are sclerosed, peripheral resistance and diastolic pressure both increases.
Sometimes, in older people, the walls of the arteries undergo a fatty degeneration and infiltration by fatty deposits (atherosclerosis) or they may become quite hardened by deposits of calcium (arterioscerosis). In either case, the flow of blood through the affected heart is impeded by the restricted vessel and high blood pressure is the result. But arteries have thick walls and can withstand high pressure for a long time without serious trouble.

About 90 percent of all cases of hypertension cannot be attributed to any particular cause. These are called essential hypertension. Most of the others can be traced to kidney diseases, such as Bright's disease, to adrenal tumors, or to congenital narrowing of important arteries, such as the aorta. Malignant hypertension is a rare but severe form of high blood pressure which does its damage quickly and may prove fatal in a few months.
 Certain types of people, frequently the heavy-set, stocky builds, seem to be more susceptible to high blood pressure than others. Heredity seems to have a bearing. Those who are inclined towards hypertension usually begin to show it in the early thirties.
Often there are few symptoms and the individual himself is not aware of the condition until a doctor checks his pressure. In some cases there are palpitation of the heart, headache, dizziness, and fatigue, but there are many exceptions to these symptoms. The eyes may reveal the condition because small blood vessels in the retina often appear different when hypertension is present. If high blood pressure is unusually severe, changes may occur in the heart and other organs. The doctor will not judge the severity of the disease merely by the height of the pressure on his instrument. Higher pressure does not necessarily mean greater risks.
One of the risks of hypertension is the direct effect upon the heart which is forced to do more work. The additional strain, particularly on the left ventricle may lead to heart trouble. Persistent high blood pressure may predispose to arteriosclerosis and the danger of coronary thrombosis. The kidneys may be affected because less blood flowing through them means less waste eliminated, and the possibility in extreme cases of uremic poisoning. If the pressure is high enough it may cause a blood vessel to rupture. If this occurs in the brain, where the walls of the vessels are thin, the result is a stroke, or apoplexy.
While there is no specific treatment for high blood pressure, much has been done in individual case, for hypertension varies with the patient. In severe cases, such as malignant hypertension, sympathectomy or cutting the sympathetic nerves in the abdominal and thoracic regions has been fairly effective in lowering the pressure. Drugs have long been used for treatment, and some have been developed in recent years which offer some promise.
There is definite cure available in Yoga for hypertension. So, you can practice Yoga asanas to relieve the problem.