Blood clots in the lungs are a serious condition that can be life-threatening for patients. Pulmonary thrombosis is usually caused by abnormal clotting of blood in the pulmonary blood vessels, resulting in complete blockage or partial blockage of the pulmonary blood vessels, causing impaired blood supply. It can cause patients to experience symptoms such as chest tightness, shortness of breath, chest pain, panic attacks, irritability, etc. When the symptoms are severe, patients may experience hemoptysis and fainting. Acute attacks can be life-threatening if not treated in time. First aid needs to be given to the patient during an acute attack of pulmonary thrombosis by keeping the patient absolutely braked and on oxygen. Patients need to be treated with anticoagulation of the blood using vitamin K antagonists, heparin and other drugs under the guidance of a doctor, and thrombolytic therapy is needed in serious cases. Pulmonary thrombosis is more dangerous, once the symptoms appear patients need to seek medical attention.