Sudden blockage of one of the pulmonary arteries adversely affects blood flow and oxygenation in the affected area. This can lead to symptoms such as sudden onset shortness of breath, palpitations, cough, and sometimes hemoptysis (bloody sputum).

Blockage of one of the major pulmonary arteries can cause more severe symptoms like intense chest pain (a sensation of pressure) and syncope (fainting). Clots forming in vessels close to the chest wall can lead to pleuritic-type pain (stabbing, knife-like) that increases with deep breathing. When these symptoms are encountered, pulmonary embolism should definitely be considered.

Simultaneous blockage of both pulmonary arteries can result in sudden cardiac arrest and death. This condition is important in differential diagnosis as it can present with similar symptoms to acute myocardial infarction (heart attack).