A sudden strong heartbeat may be a physiological phenomenon during emotional excitement or exercise, or it may be a symptomatic manifestation of diseases such as tachyarrhythmia and hyperthyroidism. 1. Emotional excitement or exercise causes sympathetic nerve excitation, which strengthens the contraction force of the heart muscle, thus causing the feeling of a strong heartbeat. Symptoms can be improved by adjusting emotions or resting, and no special treatment is needed. 2. Tachyarrhythmia. It is the feeling of a strong heartbeat caused by a heart rate of more than 100 beats per minute. Anti-arrhythmic drugs or radiofrequency ablation may be given. 3. Hyperthyroidism. The increase in thyroid hormones in the body causes over-excitement of the sympathetic nerves, which can lead to a faster heart rate. Antithyroid medication is needed to reduce symptoms by controlling thyroid hormone levels. If the heart rate suddenly becomes strong, you should consult a doctor and complete the relevant examinations, so that the doctor can diagnose the cause of the disease and give appropriate treatment if necessary.