Fast vs slow heart rate: How to know a normal heart rate

Doctor checking a patient's heart rate

With cardiovascular diseases like heart attack, coronary artery diseases, cardiomyopathy, hypertension and heart failure on the rise, discussing the heart rate becomes more necessary.

The World Health Organisation stated that cardiovascular diseases are the leading cause of death worldwide. Cardiovascular diseases cause an estimated 17 million deaths every year. About one-third of the deaths occur premature (in people under 70 years).

Measuring your heart rate will help you monitor your health to know when you are safe or in danger of a heart problem.

This article will discuss what a normal heart rate is, how to check your heart rate, causes of slow and fast heart rate and what your heart rate can reveal about your health.

What is a heart rate?

A heart rate is also called a pulse rate. The heart rate is the number of times the heart beats in one minute. The heart rate is measured in bpm

The pulse rate varies from one individual to another. It is lower when the body is at rest and increases after physical activity. 

The pulse rate increases when the body is in an active state because, at that state, the body needs more blood to supply oxygen to the muscles and other body tissues.

What is a normal heart rate?

Photo by Jair Lazaro on Unsplash

When at rest, the normal heart rate for children is 70 to 100 beats per minute. The normal heart rate at rest is 60 to 100 beats per minute for adults. You know a normal heart rate when it is within the range of 60 to 100.

A lower resting heart rate typically indicates that the heart is functioning efficiently and the cardiovascular fitness is great. For instance, athletes usually have a lower resting heart rate.

The maximum heart rate

A maximum heart rate is an individual’s highest heart rate during maximal exercise. Calculating the maximum heart rate helps you figure out your ideal target heart rate during your workout session. 

An individual’s heart rate is calculated based on age. You calculate your maximum heart rate by subtracting your age from 220. For instance, if you are 30 years old, you calculate your maximum heart rate by subtracting 30 from 225.

225-30 = 195. 

This means your pulse rate when you exercise should be up close to 195. If your heartbeat per minute is much less than your maximum heart rate when you exercise, it could mean you are not exercising well enough, or you are not putting in enough energy.

According to the American Heart Association, the ideal heart rate when carrying out a moderate-intensity exercise should be about 50-70% of the maximum heart rate, while the ideal heart rate during vigorous physical activity should be about 70-85% of the maximum heart rate.

So, if you are 30 years old (with a maximum heart rate of 195), you should aim for a target heart rate of 98-166 bpm (50-85% of your maximum heart rate. 

How to check your heart rate

To take your heart rate on your wrist:

  • Place your index and middle finger between the bone and tendon over the radial artery (found just at the base of your thumbs)
  • When you feel the pulse, count the number of beats in 15 seconds
  • Multiply the number of beats by four to get your beats per minute (bpm)

(You are multiplying by 4 because 15 seconds multiplied by 4 gives 60 seconds, which is a minute)

To take your pulse rate on your neck, follow the same procedure above, but this time, you will place your index and middle finger on your neck, close to your windpipe. 

Causes of abnormal heart rate

Photo by Ali Hajiluyi on Unsplash

A change in heart rate does not always mean you are in danger. An abnormal heart rate may be “normal”, depending on the factor affecting the heart rate. 

Some factors that can affect your resting pulse rate include:

  • Weight
  • Temperature
  • Medication side effects
  • Smoking
  • Body position
  • Smoking

Fast heart rate

There are cases where a person’s heart rate is too fast. When the heart beats too fast, it is known as tachycardia. A fast heart rate in adults is defined as a pulse rate that is over 100 beats per minute.

What is considered as a fast, slow or normal heart rate also depends on overall health and age. 

Causes of tachycardia include:

  • Anaemia
  • Caffeine consumption
  • Alcohol and drug (e.g., cocaine) use 
  • An underlying health condition
  • Fever
  • Anxiety or stress
  • Intense exercise
  • Electrolyte imbalance
  • Smoking
  • Side effects of certain medications

Slow heart rate

A slow heart rate is called bradycardia. Bradycardia is a pulse rate that is less than 60 beats per minute. A heart rate below 60 bpm is normal for athletes and people who exercise regularly.

Causes of bradycardia include:

  • Old age
  • An underlying health condition
  • Electrolyte imbalance
  • Medication side effects
  • Obstructive sleep apnoea

What your heart rate can tell about your health

Photo by Thirdman on Pexels

Your heart rate can tell the condition of your health. If the pulse rate is too high or too low, it may indicate a health problem. 

Even though a heart rate of 100 bpm is considered normal, a study found that the risk of death doubled among healthy people with a resting heart rate of above 80 bpm and tripled among people with a resting heart rate of above 90 bpm.

On the other hand, it is not uncommon for athletes to have a resting heart rate lower than 60 bpm. It is considered normal for athletes. In fact, it is often a sign of optimal heart function and fitness. 

However, for people who are not athletes or are highly physically active, having such a low heart rate could indicate a potential health problem. 

Note that it is best always to consult a health expert. If you have a low heart rate accompanied by symptoms like dizziness or fainting, chest pain or tightness and shortness of breath, you should see your doctor as soon as possible as it could be a sign of serious heart complication.

Also, even if you take your pulse rate and it is normal but still feel like your heart is beating too fast or too slow such that you are uncomfortable, do not ignore what you feel. Visit your doctor as soon as possible for advice and diagnosis. 


  1. American Heart Association. (2021). Target heart rates chart.
  2. American Heart Association. (2016, September 30). Bradycardia: Slow heart rate.
  3. American Heart Association. (2016, September 30). Tachycardia: Fast heart rate.
  4. Gellish, Ronald L et al. (2007). Longitudinal modelling of the relationship between age and maximal heart rate.
  5. Jensen, Magnus Thorsten et al. (2013). Elevated resting heart rate, physical fitness and all-cause mortality: a 16-year follow-up in the Copenhagen Male Study.
  6. World Health Organisation. (n.d.). Cardiovascular diseases.