Published March 28th, 2020 by USA Rx
We often hear about the dangers of high blood pressure, but is it possible for your blood pressure to be too low? With high blood pressure such a concern, it might stand to reason that the lower your blood pressure is, the better. While this can be true for people who are otherwise healthy without any health conditions, low blood pressure can cause bothersome and sometimes dangerous symptoms and can be a sign of an underlying medical condition.
We all have blood pressure - it’s an essential force that helps keep us alive. Blood pressure is the force, or blood flow, at which your blood pushes against the walls of your blood vessels, like your arteries, veins, and capillaries. Our bodies, including all of our tissues and organs, function using the oxygen they receive from our blood. Our heartbeat is the mechanism by which blood is pushed out of the heart and through the blood vessels. Each time our heart beats, blood is sent through the body to the organs and extremities, delivering vital oxygen.
Blood pressure is measured using two different readings that measure blood pressure at different times: systolic pressure and diastolic pressure. Systolic pressure is measured as the blood pumps out of the heart and into the arteries and can be considered a measurement of “active” blood pressure. The systolic pressure will be the first or top number listed on a blood pressure reading. The second, or bottom, number of a blood pressure reading is the diastolic pressure. This number is taken as your heart rests between beats, measuring the blood pressure in your blood vessels when the heart is not actively working. Diastolic pressure may be thought of as the “resting” pressure.
Lower blood pressure, or hypotension, is a medical condition characterized by a consistently lower than normal flow of blood to the tissues, organs, and extremities. In people who are otherwise healthy, and have no symptoms, low blood pressure is generally not a cause for concern. After all, there is so much talk about the dangers of high blood pressure that it seems like having low blood pressure would be ideal. However, low blood pressure can sometimes be a sign of an underlying medical problem, especially in people over the age of 65. Dizziness or lightheadedness can occur when the brain is left without an adequate blood supply.
There are two types of low blood pressure. The first type, known as postural hypotension or orthostatic hypotension, happens when a sudden drop in blood pressure occurs due to a person changing positions quickly, such as moving from a sitting position to standing. The second type of low blood pressure, called neurally mediated hypotension, happens when someone stands for a long period of time.
Postural hypotension is most commonly caused by dehydration, blood loss or loss of blood, anemia, and certain medications. These factors can cause your body to respond too slowly to changes in movement. As you move from sitting to standing or from lying down to sitting, your body should correct for blood pooling in the extremities by sending your heart a message to beat faster and for your blood vessels to constrict. When your body is unable to respond to these messages quickly enough, postural hypotension occurs, which can sometimes cause fainting. Postural hypotension is most commonly experienced by people taking medications to control high blood pressure, but it can also be associated with the following conditions and side effects:
Neurally mediated hypotension, on the other hand, is caused by a chance in the activity of the autonomic nervous system, and it often results in fainting. A drop or pause in heart rate can also occur. Neurally mediated hypotension occurs when there is a mixup in the signals between the heart and the brain. When the heart should be triggered to beat faster to make up for blood pooling in the extremities after standing for a long period of time, it receives an incorrect message from the brain telling it to slow down and narrow the blood vessels instead. This results in a drop in blood pressure and can cause lightheadedness or fainting due to a lack of blood reaching the brain.
There are five different categories for blood pressure. Blood pressure readings are written by the American Heart Association by placing the systolic, or “active,” number on top and the diastolic, or “resting,” number on the bottom.
Low blood pressure may not cause any symptoms. When this is the case, it’s generally ok for your blood pressure to be low. If low blood pressure does causes symptoms, they may include:
If your low blood pressure is causing you to experience unwanted symptoms like fainting and dizziness, there are steps you can take to treat and prevent it. These include:
You should be concerned about low blood pressure if it causes bothersome symptoms on a regular basis or if you experience a sudden drop in blood pressure. A sudden drop in blood pressure can be life-threatening, so you should consult your doctor immediately. Causes of low blood pressure or sudden drops in blood pressure can be caused by: