If you wake up after a nightmare and have panic attacks, you should have sinus tachycardia. The cause of the onset of the disease is related to the patient’s nightmare and fright, and the nervous stimulation causes abnormal heart conduction and increased heart rate, which manifests as panic attacks, chest tightness, shortness of breath and other discomforts. After being frightened, the panic usually lasts for a while and can be relieved by itself, so in most cases no special treatment is needed. If the panic does not improve or even worsen, you can go to the hospital for relevant examinations, such as electrocardiogram, 24-hour ambulatory electrocardiogram, etc., to exclude the organic lesions of the heart.