<unk>  is a blockage of a blood vessel, usually with a clot. It differs from thrombosis in that it can be used to describe any form of blockage, not just one formed by a clot. When it occurs in a major vein, it can, in some cases, cause deep vein thrombosis. The condition is also relatively common in the retina, and can cause partial or total loss of vision. An<unk>  can often be diagnosed using Doppler sonography (a form of ultrasound). Some medical procedures, such as embolisation, involve occluding a blood vessel to treat a particular condition. This can be to reduce pressure on aneurysms (weakened blood vessels) or to restrict a haemorrhage. It can also be used to reduce blood supply to tumours or growths in the body, and therefore restrict their development.<unk>  can be carried out using a ligature; by implanting small coils which stimulate the formation of clots; or, particularly in the case of cerebral aneurysms, by clipping.
Vascular occlusion
Ischemic compression
Vascular anomaly
Tissue stress
Articular cartilage damage
Vascular malformation
Pre-existing condition
Malignant transformation