Being Sick Has An Unexpected Effect On Your Heart Rate

Feeling under the weather affects our bodies in countless ways. Depending on the cause of illness, you may experience muscle aches, an upset stomach, fever, low energy, a lack of appetite, and more. Being sick can also impact our body's different automatic functions, such as heart rate. According to the Mayo Clinic, a healthy resting heart rate falls between 60 and 100 beats per minute. When we're sick, however, our heart rate tends to increase. It's not unusual for our heart rate to climb when we feel nervous or in the throes of vigorous exercise, but when we're feeling congested and lethargic, how is it that our heart rate manages to accelerate?

In short, it has everything to do with our immune system. When we're sick, our immune system springs into action to kick that virus to the curb. To do so requires increased circulation to our essential germ-fighting organs. This need for increased pumping of blood and oxygen throughout the body means that more is now required of our heart. As a result, we experience an uptick in our heart rate. "If a person's physical demands for more blood increases, then the heart rate is generally the first to increase to meet that demand," Dr. Mark Tuttle, a cardiologist at Banner Health, told HealthOne.

An accelerated heart rate when sick generally isn't something to fear. Rather, it indicates your body is functioning as it should be. Researchers from an early 1986 study published in the Archives of Internal Medicine monitored the heart rates of 27 sick young men for a period of 24 hours. The participants were sick with either the adenovirus, flu, bacterial pneumonia, or an undefined illness. While sick, the men's average heart rate was calculated at 84 beats per minute. Every time participants' body temperature increased by 1.8 degrees Fahrenheit, the men experienced an increase of 8.5 heartbeats per minute. A higher-than-normal heart rate continued to be observed even as the men slept. That being said, there are cases in which those with preexisting heart problems may be at risk for more serious health issues if they were to contract a cold or the flu, explains GoodRx Health.

While a cold won't always pose issues for those with heart disease, if a person were to subsequently develop bronchitis, this could cause heart rhythm abnormalities (via GoodRx Health). Those with chronic bronchitis — which is characterized by airway inflammation and respiratory symptoms that persist for more than three months over the course of two years — may also experience a faster heart rate, otherwise referred to as tachycardia, explains Advocate Health Care. Pneumonia can also cause our heart rate to quicken, according to Harvard Health Publishing. In some cases, pneumonia may boost our heart rate up to 150 beats per minute. Alternatively, if a person with heart issues were to get sick with the flu, they may become more susceptible to heart attack, irregular heartbeat, or heart failure.

All of us get sick at one point or another. Therefore, the best thing we can do to prevent an illness-related increase in heart rate is to try and stay healthy as best we can. By keeping up with routine vaccinations, eating a healthy diet, getting regular exercise, and diligently washing our hands, we can help keep germs at arm's length. If you become sick and experience an accelerated heart rate in addition to dehydration, fatigue, difficulty breathing, confusion, or chest pain, be sure to get prompt emergency care.