What is a heart rate that is too low? When a slow resting heart rate is normal and when to call the doctor

In this article you’ll find the answer to the question of what counts as a resting heart rate that is too low, what is normal for men and women, and when a slow heart rate is a reason to call the doctor. That matters, because a slow heart rate can be normal for one person, for example an athlete, while in someone else a slow heart rate causes dizziness, tiredness and shortness of breath.⁠² The BioProfile heart scan gives you an indication of where you stand today when it comes to your heart and blood vessels. The scan is not a diagnosis. It is insight, to see where you stand today and to help you make better choices in your diet and lifestyle. Finding the cause of a slow heart rate is work for a doctor.

What is too low a heart rate

A heart normally beats between 60 and 90 times a minute when you are sitting quietly, says Thuisarts, the Dutch information site run by GPs.⁠¹ A heart rate below 60 beats per minute has traditionally been called bradycardia, the medical word for a slow heart rate. The 2018 US guideline on slow heart rhythms draws a stricter line for a problem with the sinus node, the heart’s own pacemaker: a heart rate below 50 beats per minute, a pause of at least 3 seconds between beats, or both.⁠²

In plain words: below 60 is slow by the traditional cut-off. The guideline only speaks of a problem with the sinus node below 50, or when the heart pauses for longer.

What is a normal resting heart rate for men and women

The Dutch reference values come from 13,354 people aged 16 to 90 from four Dutch population studies. People with heart disease, high blood pressure or diabetes were left out of the analysis.⁠³ In men, the typical resting heart rate fell after puberty to about 65 beats per minute and rose again in old age to 73. Only 2 in 100 healthy men had a heart rate below about 50.⁠³ In women, the heart beats slightly faster. Across the age groups, the typical heart rate was between 67 and 72 beats per minute, and the lowest 2 in 100 were below 46 to 53, depending on age. Women aged 20 to 29, for example, had a typical heart rate of 67, and 2 in 100 were below 48.⁠³

What this means for you: a resting heart rate between about 50 and 60 still falls within the Dutch normal values for healthy adults. But a small group of healthy people have a lower one. You can find all the normal values by age on the page about a normal heart rate.

When a slow heart rate is normal

For some people, such as younger people and athletes, a slower heart rate is normal and no action is needed.⁠² In a small Australian study, 22 national-level triathletes had an average resting heart rate of 53.8 beats per minute, compared with 72.1 in 7 people who did little exercise: 34 per cent lower. Of the triathletes, 68.2 per cent had a slow sinus rhythm.⁠⁵

Among 465 elite endurance athletes wearing a heart monitor, the heart rate of 38 per cent dropped at some point to 40 beats per minute or lower, and in 2 per cent to 30 or lower. These slow heart rates, and pauses of 2 to 3 seconds, were common and well tolerated. Over 5.5 years, these slow heart rates were not linked to more adverse outcomes. Both inherited make-up and fitness each played their own part in how low the heart rate dropped.⁠⁴

In plain words: a trained heart often beats slowly at rest, and in these athletes that slow rhythm was not a sign of a problem. What too little movement does to your body is covered in what too little movement does to your body.

When a slow heart rate points to something

A slow heart rate can cause dizziness, tiredness and shortness of breath. If the heart cannot pump enough blood around the body, this may lead to heart failure or a sudden cardiac arrest.⁠² A related condition is sick sinus syndrome. Two US population studies followed 19,893 people aged 45 and over for an average of 17 years and found 213 new cases. People with the syndrome died more often, developed heart failure and atrial fibrillation (an irregular heart rhythm) much more often, and were many times as likely to receive a pacemaker.⁠⁶

What this means: the condition is rare, but it weighs heavily when it is there. A slow heart rate that comes with symptoms deserves to be looked at by a doctor.

Is a low resting heart rate a risk?

A meta-analysis of 46 studies, together covering more than 1.2 million people from the general population, looked at resting heart rate and death. Every 10 extra beats per minute at rest went with a slightly higher risk of death, and above 80 beats per minute the risk was clearly higher than in the lowest group. From 45 beats per minute upwards, the risk rose steadily as the heart rate went up.⁠⁷

A US study of 6,733 adults aged 45 to 84 without heart disease, who were followed for 10 years, looked directly at the slow end. Of those who were not taking a medicine that lowers the heart rate, 5.3 percent had a heart rate below 50. That slow heart rate was not linked to more heart disease or a higher risk of death, while a heart rate above 80 was linked to a higher risk of death. Among the 902 people who did take such a medicine, such as a beta blocker or a calcium channel blocker, often used for high blood pressure, a heart rate below 50 went with a clearly higher risk of death.⁠⁸

What this means for you: in these studies, a slow heart rate without symptoms and without such a medicine did not bring any extra risk. With a medicine that slows the heart, the same low number meant something different.

When to call the doctor

Call your GP or the out-of-hours GP service straight away if, along with a change in your heart rate, you also notice any of the following: pain or pressure in your chest that does not go away after a few minutes, a feeling that you are about to faint, shortness of breath, confusion, difficulty speaking or a drooping face, or a heart rhythm that suddenly changes and does not settle at rest.⁠¹ The heart symptoms women report are covered in a separate article on heart symptoms in women.

What the heart scan measures and what it does not

The heart scan gives an indication of where you stand today when it comes to your heart and blood vessels, as a starting point you can come back to later. The scan cannot show why your heart beats slowly, and it cannot tell a trained heart apart from a problem with the sinus node. The scan is not a diagnosis. Finding the cause is work for a doctor.

In summary

In this article you read that a heart at rest normally beats 60 to 90 times a minute, that below 60 has traditionally been called slow, and that only a small group of healthy Dutch adults are below about 50. In many athletes the heart beats much more slowly without any harm. A slow heart rate deserves attention when it comes with symptoms or with a medicine that slows the heart, and fainting, chest pain or shortness of breath with a change in your heart rate is a reason to call your GP straight away.