Heart fluttering means that it may be related to mental tension, but also seen in hyperthyroidism, premature beats and other diseases. 1. Nervousness: the secretion of adrenaline in the body increases when nervousness, adrenaline can increase the contraction rate of the heart, accelerate the heart rate, the human body can appear heart fluttering and beating feeling. 2. Hyperthyroidism: the thyroid hormone level in patients with hyperthyroidism is significantly higher, which can lead to a faster heartbeat and increased heart rate, and patients can experience symptoms of fluttering heartbeat. 3. Premature beats: premature beats can be categorized into atrial premature beats and ventricular premature beats, which are early heartbeats. Frequent premature beats can lead to heartbeat rhythm disorders, and patients can feel the symptoms of heartbeats. Mental tension caused by heartbeat should pay attention to stabilize mood, the symptoms are obvious or persistent patients, should go to the hospital in time, to clarify the specific cause and according to the medical advice for treatment.