A hematoma is an area of accumulated blood. It may appear in an organ, in the tissue surrounding these organs, or directly under the skin. It is usually caused by a ruptured blood vessel, allowing blood to flow out before clotting occurs. In the case of rapid formation of a blood clot, hematoma can be controlled by the body, but in cases of larger, more serious injuries, clotting disorders, or anticoagulation medication which delays the control of bleeding, a significant hematoma can form. It can be benign, particularly in small skin hematomas following trauma in a healthy individual, but depending on its size and location, it can have serious consequences, as in a cerebral hematoma which can, by the space it occupies in the inextensible skull, lead to compression phenomena on brain structures .