When the blood leaves the heart is driven by some force to circulate through the body. Pressure must be high enough to circulate to carry oxygen and nutrients to the cells and extract waste from it.
When the pressure is too high is known as hypertension, and it's a serious problem, if it is not controlled can have deadly consequences. But when the pressure is low or weak, this problem is called hypotension and can also be serious, because the whole body can not get oxygen and nutrients needed by every cell.
Although hypotension is not normal, there are always people who live with a low pressure (up to certain limits), without affecting their activity or their quality of life.
