The normal heartbeat range is 60-100 beats per minute. If the heartbeat is greater than 100 beats per minute, it is defined as tachycardia. There are many causes of tachycardia, and there may be secondary conditions such as heart failure, hypovolemia, hyperthyroidism, or the heart itself may have arrhythmias such as sinus tachycardia, rapid atrial fibrillation, atrial flutter, and paroxysmal supraventricular arrhythmias. At the onset of symptoms, an electrocardiogram should be done as soon as possible, and further tests of thyroid function and electrolytes are recommended to clarify whether there is a cause for the fast heartbeat.