Left heart enlargement suggests an increase in the size of the left heart and can be seen in conditions such as hypertension and aortic stenosis. Enlargement of the left heart is a radiographic manifestation of an increase in the size of the left heart, which may be seen in some patients simply as enlargement of the left heart, and in other patients may be accompanied by ventricular hypertrophy. In the early stage of enlargement, it is a compensatory manifestation, and myocardial contractility will increase at the same time with the enlargement, and when the heart increases to a certain degree, myocardial contractility will be reduced accordingly. There are many reasons for left heart enlargement, and common diseases include hypertension, which leads to an increase in cardiac afterload and compensatory left heart enlargement. Left heart enlargement can also be seen in aortic stenosis, where an increase in volume promotes left heart enlargement. There are many other diseases of left heart enlargement, usually pay attention to strengthen the follow-up, have obvious symptoms should go to the hospital in a timely manner, under the guidance of the physician to find the cause and give treatment.