If the clot occurs in an artery in the brain, a person can have a stroke. Cancer patients are especially vulnerable to disability and death from abnormal clot formation inside the blood vessels, particularly in the veins. Symptoms may be totally different, strictly depending on the position of the clot. Clotting can be localized, but it can also be generalized, such as in a condition called Disseminated Intravascular Coagulation, which also occurs when we die. Up to a point, aggressive medical management can reverse it.
Clots can stay where they form or travel to a different location.
Whether the clot forms on the spot or travels, the size of the clot is secondary in importance to the location of the clot and the specifics of the area occluded. In general, clots in areas with less collateral circulation are more serious and may be life threatening. Causes There are hundreds of possible factors that can precipitate blood clots. Our body is so designed that ANY circulatory disturbance in the blood flow from any cause can result in blood clots. This multiplicity of possible causes is a reason that circulatory problems and thrombosis are a major medical problem today.