When a small clot is lodged in the lungs, it is called a pulmonary embolism. This hinders blood flow to the lungs.
Through a complex network of arteries and veins the circulatory system carries blood to all parts of the body. The veins are the part of the circulatory system that returns deoxygenated blood to the heart and lungs.
Sometimes irregularities in the artery wall cause clots (thrombus, plural thrombi) in the blood, especially in places where the blood flows slowly, such as at a vein valve. Once a clot has formed, it starts to grow in the vein by deposition of fibrin (clotted protein) and red blood cells.
Except for the chance phlebitis and obstruction of blood flow there is also a high risk that the clot or part thereof will break loose and be entrained in the circulation. These ‘mobile’ clots can eventually settle through the heart into the small blood vessels of the lungs.
Such a stuck clot is called a pulmonary embolism. An embolism can impede blood flow to the lungs, shortness of breath, dizziness, cough and chest pain as a result. Pulmonary embolism is a medical emergency. Therefore, immediate medical intervention is required.
