A normal adult resting heart rate is generally between 60 and 100 beats per minute (bpm). If you have bradycardia, your heart rate is less than 60bpm.
Depending on the cause, bradycardia can last a short time or a long time.
Bradycardia (a heart rate of 40 to 60bpm) can be normal if:
• you're sleeping or resting
• you are a young, healthy adult
• you're very physically fit
You may notice your heart rate is slower than normal if you have a wearable device that measures your heart rate.
Bradycardia can sometimes be a sign of problems with your heart.
What are the symptoms of bradycardia?
If you have any of these symptoms and you have a slow heart rate, you should see a doctor straight away or go to your nearest emergency department.
Symptoms of bradycardia can include:
• feeling faint, lightheaded or dizzy
shortness of breath when moving or exercising
• feeling tired or weak
Sometimes bradycardia can lead to:
low blood pressure
fainting
angina or chest pain
confusion or loss of consciousness
Some people have no symptoms of bradycardia
What causes bradycardia?
damage to your heart from conditions such as a heart attack or cardiomyopathy
hypothyroidism (when your thyroid gland doesn't make enough thyroid hormone)
an electrolyte (salt) imbalance in your blood
a congenital heart defect (heart disorder present at birth
some medicines
sleep apnoea
When should I see my doctor?
See a doctor straight away or go to your nearest emergency department if you have chest pain, confusion or loss of consciousness.
If you have a pulse rate that is less than 60bpm and have any symptoms, see your doctor. It might help to note the times you notice your heart is beating slowly, and how you're feeling at the time.