Common causes of an irregular pulse include heart disease, imbalanced electrolytes in the blood and changes in the heart muscle, according to WebMD. Other causes include injuries after heart attacks and normal recovery after heart surgery.
Some causes of an irregular pulse are harmless, while others are signs of a more serious condition, explains WebMD. Premature atrial contractions are harmless forms of arrhythmia that do not require treatment. They are extra beats in the heart that start in its upper chambers. Atrial flutters occur as a result of heart surgery, usually within the first week. Cardiologists test irregular pulses to ensure they pose no serious medical threat.
Other causes of an irregular pulse, or arrhythmia, include smoking, drinking caffeine or stress, states Mayo Clinic. People suffering from diabetes are more likely to have irregular heartbeats, as are people who have an over-active or under-active thyroid gland. Abusing drugs or taking certain prescription medications can cause an irregular pulse.
A normal heart rate is between 60 and 100 beats per minute, notes Mayo Clinic. Athletes sometimes have resting heart rates of less than 60 beats per minute. This does not indicate heart disease. People temporarily develop faster heart rates when they exercise. Temporary increases or decreases in heart rates are not always signs of a serious medical problem.