Rapid heartbeat, chest tightness and shortness of breath may be caused by physiological factors or pathological factors, such as heart disease, fever, hyperthyroidism, anemia and medication. 1. Physiological factors: strenuous exercise, drinking strong tea, coffee, emotional tension, stress and other reasons can lead to tachycardia, causing related symptoms. 2. Pathologic factors: (1) Heart disease: coronary heart disease, coronary artery disease, heart failure and so on will lead to tachycardia, cause related symptoms, and heart function abnormality is closely related. (2) Fever: increased body temperature will lead to accelerated blood circulation, causing tachycardia, resulting in corresponding symptoms. (3) Hyperthyroidism: Hyperthyroidism directly promotes accelerated metabolism and accelerated blood circulation, causing the corresponding symptoms. (4) Anemia: Insufficient supply of nutrients to the body of anemic people will lead to accelerated blood circulation and promote the body’s metabolism, resulting in corresponding symptoms. (5) Medication: The application of drugs such as adrenaline, atropine and digitalis will cause changes in the excitability of the nerves, leading to tachycardia and corresponding changes. Symptoms such as rapid heartbeat, chest tightness and shortness of breath accompanied by obvious respiratory abnormalities, and insufficient blood supply to the brain require prompt medical attention and standardized treatment under the guidance of clinicians.