The thickening of the pulmonary artery trunk is usually caused by pulmonary artery hypertension or chronic obstructive pulmonary disease. In patients with chronic obstructive pulmonary disease, thickening of the pulmonary artery trunk is found during chest radiographs when the disease reaches its end stage, which is due to prolonged hypoxia that causes pulmonary hypertension. When patients are diagnosed with pulmonary artery trunk thickening, most of them have pulmonary hypertension, and they usually have breathing difficulties. In addition, heart disease can also cause pulmonary artery hypertension, for which vascular intervention is recommended to reduce the symptoms.