An embolism is the lodging of an embolus, a blockage-causing piece of material, inside a blood vessel. The embolus may be a blood clot (thrombus), a fat globule (fat embolism), a bubble of air or other gas (gas embolism), or foreign material. Signs and symptoms of pulmonary embolism (PE) include unexplained shortness of breath, problems breathing, chest pain, coughing, or coughing up blood.