What Causes a Slow Heart Rate?

Reviewed on 10/12/2022
A doctor holding a red heart figure in hands
Causes of a slow heart rate may include problems in the conduction pathways of the heart, problems with the sinoatrial (SA) node, heart damage from heart disease or a heart attack, some heart medications, and metabolic problems.

A person’s heart rate is the number of times their heart beats per minute (BPM). According to the American Heart Association, a normal adult resting heart rate is between 60 beats per minute (BPM) and 100 BPM for people 15 years and older. 

A resting heart rate below 60 BPM is considered a heart rate that is too slow (also called bradycardia). However, what’s considered too slow can depend on a person’s age and physical condition. 

Heart rate may fall below 60 BPM during sleep, which is normal. 

Elderly people and those who take medications such as beta-blockers are more prone to bradycardia.

A slow heart rate can also be common in athletes and those who are physically fit. 

Causes of a slow heart rate may include: 

  • Problems in the conduction pathways of the heart that don’t allow electrical impulses to pass properly from the atria to the ventricles
  • Problems with the sinoatrial (SA) node, considered the heart’s natural pacemaker
  • Heart damage from heart disease or a heart attack
  • Some heart medications that have slow heart rate as a side effect
  • Metabolic problems such as low thyroid hormone (hypothyroidism)

What Are Symptoms of a Slow Heart Rate?

A slow heart rate (bradycardia) may cause inadequate blood flow to the brain which can result in symptoms such as:

What Is the Treatment for a Slow Heart Rate?

If a slow heart rate (bradycardia) only occurs sometimes or is borderline slow, treatment may not be needed.

Athletes and people who are physically fit and who have a slow heart rate do not need treatment.

Treatment for severe or prolonged slow heart rate may include: 

  • Adjusting or stopping medications that cause slow heart rate as a side effect
    • Never stop taking a medication or change the dosage or regimen without first talking to your doctor
  • Pacemaker to regulate the heart’s rhythm

What Are Normal Heart Rates by Age?

To find your heart rate, check your pulse, which can be felt on your:

  • Wrists
  • Inside of the elbow
  • Side of the neck
  • Top of the foot

Place your finger (not your thumb) over your pulse and count the number of beats in 60 seconds to get your heart rate. 

Normal Heart Rates by Age
Age Range Heart Rate (beats per minute, or BPM)
Newborn 100-160
0-5 months 90-150
6-12 months 80-140
1-3 years 80-130
3-5 years 80-120
6-10 years 70-110
11-14 years 60-105
15 years and older 60-100

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Reviewed on 10/12/2022

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