Occasional premature beats are called episodic premature beats, which can be asymptomatic or have palpitations or pause in heartbeat; frequent premature beats are called frequent premature beats, which mostly cause palpitations, chest tightness, fatigue, dizziness and other discomforts. Generally speaking, occasional premature beats are mostly physiological, while frequent premature beats are mostly pathological and are commonly associated with coronary heart disease and myocarditis. Premature beats occurring at rest or with a slow heart rate are mostly physiological, while those occurring during exercise or with a fast heart rate are mostly pathological. Those caused by exertion, irregular work and rest, emotional stress, excitement, anxiety, smoking, drinking alcohol, and drinking strong tea and coffee are physiological; if organic heart disease such as coronary artery disease and cardiomyopathy already exists, those occurring are mostly pathological premature beats. Physiological premature beats are risk-free and do not affect people too much. The majority of patients with pathological premature beats have a good prognosis after treatment, and only a few with severe underlying cardiac disease or ionic disorders can induce malignant arrhythmias.