If you wake up with an accelerated heartbeat, it may be caused by abnormal neural regulation, arrhythmia and blood pressure, as follows: 1, abnormal neural regulation: If you wake up suddenly during sleep, the symptoms of an accelerated heartbeat will often appear, and the symptoms will generally disappear within a few minutes, especially if you are suddenly woken up during deep sleep or wake up from a nightmare during deep sleep, you will definitely have an accelerated heartbeat. This is a sudden excitation of the sympathetic nerve causing rapid heartbeat, this situation does not require special concern and does not require treatment. 2, arrhythmia disease: If the rapid heartbeat lasts for a long time, it is best to go to the hospital to check the 24-hour electrocardiogram to see if there is an arrhythmia disease. 3, blood pressure abnormalities: you can check the blood pressure to see if the sudden increase in blood pressure caused by the rapid heartbeat.