Hypotension or low blood pressure occurs either when there is not enough force exerted on the blood by the heart to move the blood thorough the vessels, or the vessels themselves are not capable of containing the heart's force well enough to properly channel it through the body. As body tissues depend on the blood for nourishment at all times, low blood pressure can be a very serious and potentially lethal condition.
Conditions associated with Hypotension
Shock is an acute (coming on suddenly) condition that results from reduced blood pressure. Specific subtypes of shock are named after what has caused the low blood pressure to occur:
- Cardiogenic Shock results from a heart that cannot create enough pressure to insure adequate circulation.
- Septic Shock occurs when an infection affecting the whole body causes blood vessels to dilate, thus reducing blood pressure.
- Hypovolemic Shock occurs when the intravascular (inside the vessels) blood volume becomes too low. In other words, it occurs when there is a reduction in the amount of blood in the body. This type of shock typically occurs when a person loses blood from a gun shot wound, or similar trauma.
- Anaphylactic Shock occurs in the context of a severe allergic reaction.
The low blood pressure accompanying shock causes serious, even lethal problems. Blood carries oxygen. When blood pressure is very low organs such as the kidneys, the brain, and the liver cannot get enough blood. If these organs do not get enough blood, they do not get enough oxygen. Any prolonged reduction in organ oxygen supply can cause the organs to die.
Serious low blood pressure problems usually occurs only in very sick, hospitalized patients. We will not discuss them further. The rest of this document will be concerned exclusively with Hypertension.
