Pulmonary vein thrombosis is a disease of the lungs caused by the obstruction of an embolus, mostly caused by the dislodgement of blood clots from other sites and by air embolism. Common symptoms in patients with pulmonary vein embolism are chest tightness, chest pain, and rapid breathing, and the patient may experience cyanosis. On auscultation, wet rales or rales in the lungs can be heard, and in severe cases, pleural friction sounds can be heard, and in severe cases, pleural effusion can occur, which can lead to cardiopulmonary failure, circulatory system diseases, and even shock and death if not treated correctly and timely. The most important manifestation of pulmonary vein embolism is difficulty in breathing, because the embolus causes obstruction of blood flow, so that the body can not be gas exchange.