Hemorrhage

This is a hemorrhage due to a rupture of blood vessel wall or increased permeability. Capillary bleeding can be caused by blood stasis in capillaries or minor injuries. It is a consequence of many clinical disorders, known as hemorrhagic diathesis. Arterial or venous ruptures occur due to blood vessel wall injuries – trauma, atherosclerosis, high blood pressure, tumor-induced vascular wall erosion, etc. Bleeding can be external or internal. Internal hemorrhage occurs when blood leaks into tissue or organ. Such hemorrhage is also called hematoma. Hematomas can be small or very large (can also be a cause of death), for example, bleeding into the brain. Small 1-2 mm hematomas on the skin, mucous membranes, or serous membranes are called petechiae. They occur due to increased permeability of blood vessel walls, decreased platelet count, or altered platelet function. Multiple petechiae are called purpura. The causes of purpura are the same as petechiae, and they also occur as a result of bruises, vasculitis, or vascular fragility. When blood vessels rupture, blood accumulates in body cavities. The clinical outcome of hemorrhages depends on the volume of lost blood and the speed of bleeding. If a large amount of blood is rapidly lost, hemorrhagic (hypovolemic) shock occurs. The clinical course of hemorrhages also depends on the bleeding site: bleeding due to minor soft tissue trauma is not dangerous, but bleeding of the same intensity, from a ruptured brain arteriole, can result in the patient’s death due to complications.

Source | Glossary of Most Commonly Used Biomedical Terms and Concepts | Lithuanian University of Health Sciences | Academician Professor Antanas Praškevičius, Professor Laima Ivanovienė