Bleeding may result from abnormalities in
Blood vessels
Collagen is a protein that is important in maintaining strong blood vessels in the body. When collagen is abnormal or abnormal substances in the blood get into vessel walls, the vessels weaken and bleeding can develop.
Fragile blood vessels cause bleeding under the skin, leading to tiny red, purple or brown spots on the skin (petechiae), slightly larger spots that look like bruises (purpura), or still larger areas of bruising (ecchymoses). They may appear red or purple in people with lighter skin and brown or black in those with darker skin. Most disorders caused by fragile blood vessels do not cause serious blood loss. The genetic disorder hereditary hemorrhagic telangiectasia is an exception.
Abnormalities of collagen in the blood vessels may occur in scurvy (due to lack of vitamin C in the diet) and in Ehlers-Danlos syndrome and other rare hereditary connective tissue disorders, including Marfan syndrome, osteogenesis imperfecta, and pseudoxanthoma elasticum, leading to an increased risk of bleeding in these disorders.
Blood vessels can also be weakened by deposits of abnormal proteins in their walls as occurs in amyloidosis, cryoglobulinemia, and hypergammaglobulinemic purpura, or by inflammation as in autoimmune vasculitis. For example, bleeding may be a prominent feature of immunoglobulin A–associated vasculitis, an inflammation of small blood vessels that is common during childhood.
Usually, doctors can determine whether bleeding is due to abnormal blood vessels based on symptoms and an examination. Sometimes, specific tests are needed to confirm disorders that are causing the blood vessel abnormality.
Treatment focuses on controlling the bleeding when possible and providing supportive care. Many people require iron therapy to replace iron lost due to repeated mucosal bleeding (see treatment of Iron Deficiency Anemia). Some people require blood transfusions.
