Pulmonary Embolism is caused by deep vein thrombosis which forms blockage of an artery in the lungs by a substance that is moved from elsewhere in the body through the bloodstream which is known as embolism. Symptoms of this disease include chest pain, cough, and shortness of breath. The blood clot in the leg appears as red, warm, swollen and painful. Low blood oxygen levels, rapid breathing, mild fever and rapid heart rate are the signs of Pulmonary Embolism. Low blood pressure and sudden death are the signs of Pulmonary Embolism. The disease is diagnosed by CT scan, chest X ray, electrocardiography, pulmonary angiography, venography, MRI, D- dimer test. Heparin and warfarin are anticoagulants used in the treatment of pulmonary embolism. Thrombolytics which are clot dissolvers prevents the formation of new clots. A thin tube called a catheter will suction large clots are used in treatment. Doctors will recommend open heart surgery in severe cases.