19-year-old what causes tachycardia?

Tachycardia in 19-year-old patients is generally considered to be caused by drinking strong tea, drinking coffee, eating spicy and stimulating food, mental stress, overwork, strenuous exercise, excessive psychological pressure, etc.; it may also be caused by hyperthyroidism, fever, heart failure, myocardial ischemia, myocardial infarction and other diseases.