Pulmonary Embolisms - Blood Clots that Can Be Lethal

A pulmonary embolism occurs when a blood clot lodges in one of the arteries located in your lungs. The source of the majority of such blood clots involved in a pulmonary embolism is the legs, but they can also make their way from the arms, pelvis, and heart. In a pulmonary embolism, the clot will travel through the larger vessels of the lung into the smaller one until it can go no further, blocking the vessel and cutting off that section of the lung from receiving blood. When this happens, the affected region of the lung dies from lack of blood and oxygen; this is known as an infarction. A pulmonary embolism can be fatal, and it is one of the leading causes of hospital death, as patients recovering from traumas and surgeries are at high risk.

A blood clot is comprised of platelets, cells that repair injured blood vessels, tangled together with red blood cells and a kind of protein called fibrin. Blood clots usually form to aid in the stopping of bleeding when an injury occurs, but they can also form for no reason. A clot that forms and remains in a vein is known as a thrombus; one that travels to other areas is an embolus. An embolus can also be a substance like a bit of a tumor or a fat globule that enters the bloodstream. Most pulmonary embolisms are precipitated by clots that form in the legs, and there is no way to predict when such a clot will break free and begin the journey that will bring it to the lungs, where all of the blood in the body passes every time it circulates through the heart.

Some of the reasons for blood clots include an individual being confined to a bed because of a stroke, surgery, or a traumatic injury, where clots can form in the arms and legs due to long periods of inactivity that decrease blood flow. Pulmonary embolisms are the third leading cause of death in hospital patients, who develop clots while they are recuperating. Traveling for hours on end, all while sitting in the same position, can be a factor in clot formation, as can a recent surgery. Obesity, heart disease, and pregnancy all add to the risk of having a clot come into being.