1. The Vasomotor Center Controls Blood Pressure
A sudden drop in blood pressure (hypotension) is due to an environmental or internal factor affecting the vasomotor center (VMC) which controls the constriction and dilation of blood vessels. We will look at four different factors that can cause a sudden drop in blood pressure, examining how each inhibits the VMC, thereby causing blood vessels to dilate (expand) and blood pressure to subsequently drop. The most common sort of dramatic drop in blood pressure is known as orthostatic hypotension. This means that blood pressure drops dramatically as you stand up. People experiencing this type of hypotension generally feel dizzy and shaky. In extreme cases, they may pass out.
2. Baroreceptor Activity Affects Blood Pressure
Baroreceptors are physiologic devices that measure the pressure in your aortic arch and carotid arteries. When pressure increases, baroreceptors stretch and send a signal to your brain. The brain then tells the heart whether it needs to increase or decrease its rate and force of contraction. If something happens to stretch baroreceptors unexpectedly, the brain may send a signal to the heart which causes it to slow down and contract less forcefully. This dramatic difference impacts blood pressure throughout the body and causes it to drop suddenly and unexpectedly.
3. Severe Pain Causes Drops in Blood Pressure
When in severe pain or after a bad emotional surprise, the body starts to go into shock. One of the main consequences of shock is decreased perfusion. Perfusion is simply how blood filters through the tissues of the body and is carried to all extremities. When in shock, blood tends to pool in the vein and other peripheral parts of the circulatory system, decreasing the amount of blood being transported to the heart. With less blood to pump, heart rate increases and blood pressure drops. This accounts for fainting in people experiencing severe pain or who have just learned disturbing news.
4. Hemorrhaging Causes Drops in Blood Pressure
It probably goes without saying that a severe bleed causes a drop in blood pressure. A significant loss of blood causes the body to go into what is known as hypovolemic shock. As the body loses blood, there is less blood available to perfuse organs and keep the body running on an even keel. The heart must work harder to keep blood flowing to vital organs like the brain and kidneys. As blood volume decreases, the heart cannot pump fast enough to maintain pressure with less blood. The result is a drop in blood pressure.
5. Do Not Take Extra Anti-Hypertensive Medication
People with high blood pressure sometime make the mistake of thinking that the lower the blood pressure, the better, no matter how low it goes. This way of thinking may lead to taking extra prescribed medication or doubling up on medication. Different blood pressure medications act in different ways, and some medications may cause decreased blood pressure even though they were prescribed to act on an entirely different condition. If you are taking a battery of drugs that includes one for high blood pressure, make sure you consult with your doctor before making any changes. Switching things around on your own could cause you to experience a sudden drop in blood pressure.
