In every warm blooded mammal, heart plays a critical role. It takes in impure blood from the body through veins, purifies it and pumps it out through arteries. Of course, the fluid (blood is a fluid) meets resistance while flow through arteries and veins, creating some friction and pressure. These are at the lowest at the point blood is stored in the ventricles, heart and maximum when it is collected at both the ends in arms.
Through machines like sphygmomanometer, this difference of pressure with every heart-beat (there are 72 per minute in an average human) can be calculated. The two ends are called systole and diastole measuring high pressure and low pressure respectively. The pulse rate of a healthy adult will read 120 at systolic peak and 80 at diastolic bottom.
Different forms of blood pressure
If there is a rapid growth in this pressure, this means that the person may be under tremendous stress. His diet may also be faulty. Hormonal problems, insomnia, certain diseases relating to heart can also bring drastic changes in blood pressure. A person may have healthy systoles count but regressive diastole. Then he is supposed to suffer from low pressure. He will be sentenced to collapsing or feeling numb at odd intervals. The person may also suffer from profuse sweating.
If the systole is high and the diastole normal, the person is believed to suffer from hypertension or high blood pressure. He would then have no control over anger, added sugar or salt in his food would be harmful for his health and he may also have digestive problems. It also needs to be stated that a huge difference in the blood pressure range may reflect that blood is deficient of oxygen and iron. It is useful to check hemoglobin count periodically.