heart rate higher when sick

Understanding Elevated Resting Heart Rate: A Closer Look at Resting Heart Rate of 120 When Sick

Resting heart rate is a crucial indicator of cardiovascular health, reflecting the number of heartbeats per minute when the body is at rest. Typically, a normal resting heart rate for adults ranges between 60 and 100 beats per minute. However, there are instances when the resting heart rate may spike, especially during illness. In this article, we will delve into the phenomenon of a resting heart rate of 120 when sick, exploring the potential causes, implications, and the importance of monitoring heart health during periods of illness.

Resting Heart Rate Basics:

Before delving into the elevated resting heart rate when sick, let’s establish a baseline understanding of resting heart rate. Resting heart rate is influenced by various factors, including age, fitness level, and overall health. Athletes, for example, often have lower resting heart rates due to their cardiovascular conditioning. On the other hand, illness can trigger an increase in resting heart rate, offering valuable insights into the body’s response to infection or stress.

Resting Heart Rate and Illness:

When individuals fall ill, the body initiates a series of physiological responses to combat the invading pathogens. One of these responses involves an increase in heart rate. This heightened heart rate is a natural part of the body’s defense mechanism, as it helps pump more blood and oxygen to the organs and tissues, aiding in the fight against infection.

Resting Heart Rate of 120 When Sick:

A resting heart rate of 120 when sick may sound alarming, but it’s essential to recognize that the degree of elevation can vary based on the severity and type of illness. In some cases, a mild infection may cause a modest increase, while more serious conditions could lead to a substantial spike. It’s crucial to note that an isolated instance of an elevated resting heart rate during illness may not necessarily indicate a chronic issue, but persistent or extreme cases warrant attention and medical evaluation.

Common Causes of Elevated Resting Heart Rate When Sick:

  • Fever: Elevated body temperature, often associated with illness, can lead to an increased heart rate as the body works harder to cool itself down.
  • Dehydration: Illness can lead to dehydration, causing a drop in blood volume and subsequent increases in heart rate to maintain adequate blood flow.
  • Inflammation: Inflammatory responses triggered by infections or illnesses can contribute to an elevated resting heart rate.
  • Stress Response: The body’s stress response to illness can prompt the release of stress hormones, such as cortisol and adrenaline, leading to an increased heart rate.

Monitoring and Seeking Medical Attention:

While a temporary increase in resting heart rate during illness is generally normal, prolonged or extreme elevations warrant medical attention. Monitoring your resting heart rate regularly, especially during illness, can provide valuable information about your overall health. If you consistently observe a resting heart rate of 120 or higher when sick, consult with a healthcare professional to rule out any underlying issues and determine an appropriate course of action.


Understanding the dynamics of resting heart rate during illness is crucial for maintaining overall health and well-being. While a resting heart rate of 120 when sick may be a natural response to infection or stress, it’s essential to be vigilant and seek medical advice if necessary. Remember, your heart rate can serve as a valuable indicator of your body’s condition, allowing you to take proactive steps towards better health.