As your heart beats, it pumps blood throughout your body, giving the oxygen and energy it needs to thrive. As blood moves throughout the body, it pushes against the walls of the blood vessels. The force that’s exerted on the blood vessel walls by circulating blood is known as blood pressure.
Blood pressure readings are expressed as a fraction; 120/80, for example. The top number represents systolic blood pressure, the amount of pressure placed on the arteries when the heart muscles contract. The bottom number, diastolic blood pressure, represents blood pressure in between heartbeats. Blood pressure is considered normal when the top number is between 90 and 120 and the bottom number is between 60 and 90. A reading that’s lower than 90/60 is considered hypotension, or low blood pressure. There are several factors that can cause low blood pressure. Here’s a look at some of the most common.
Bradycardia, or slow heart rate, is one of the most common causes of low blood pressure. A heart rate that’s considered too slow varies and depends on each individual’s age and overall health; for instance, older people are more prone to a slow heart rate. For the average adult, a resting heart rate that’s less than 60 beats per minute (BPM) is considered a slow heart rate, though there are exceptions to this.
For example, an otherwise healthy average adult’s heart rate may fall under 60 BPM while they are sleeping. When the heart beats too slowly, lower levels of blood is being pushed through the heart, and as a result, less pressure is being placed on the walls of the arteries. Therefore, bradycardia can be marked by low blood pressure. In addition to low blood pressure, other bradycardia symptoms include fatigue, lightheadedness, shortness of breath, and confusion.