A low heart rate, called bradycardia, is anything below 60 beats per minute. The average human heart beats 60 to 100 times per minute. In some cases, bradycardia does not cause complications, but it can cause problems if the heart is not pumping enough blood to the body.
A low heart rate can cause dizziness, fainting, weakness, sleep problems, confusion, difficulty breathing and chest pains. It may also cause you to tire out more easily during physical activities.
Bradycardia can be caused by heart conditions, including tissue degeneration related to aging, damage from heart attack, congenital heart defects, complications related to heart surgery and infection of the heart tissue.
Other possible causes include underactive thyroid, excessive iron in the organs, medications that lower blood pressure or treat psychosis, certain diseases (including lupus) and sleep apnea.
Age is the highest risk factor, according to the Mayo Clinic. Other risk factors include those that increase the risk for heart disease such as drug use, smoking and high cholesterol.
Treatment is often aimed at the underlying cause. Your doctor may change your medication if that is the cause. A pacemaker may also be implanted to maintain a proper heart rate.