When the heart thumps uncomfortably when you are quiet, you should go to the hospital to have a 24h dynamic electrocardiogram (ECG) to determine the cause of the problem and to define the treatment plan. Normal people’s heart rate is 60~100 beats per minute when they are quiet, when the heart rate is too fast, you will feel uncomfortable when your heart is thumping. The causes of rapid heart rate can be physiologic, such as rapid heart rate during strenuous exercise and emotional excitement. It can also be pathologic, such as various arrhythmias. If your heart feels uncomfortable when you are quiet, you may have an arrhythmia and should be referred to the hospital for a 24-hour ambulatory electrocardiogram (ECG). 24-hour ECG monitors your heart rate and rhythm over a 24-hour period, which can help you find the cause of your heart palpitations and treat the cause of your discomfort. When arrhythmias such as atrial fibrillation, premature beats, etc. are present and there are obvious symptoms of discomfort, treatments include the use of rate-controlling medications such as metoprolol, propafenone, etc., cardiac electrophysiology, and surgical procedures such as radiofrequency ablation. If you feel unwell, it is recommended that you seek medical attention promptly to avoid delays.