Bleeding may result from abnormalities in
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), red or purple blemishes or bruises (purpura), and bruising. Most disorders caused by fragile blood vessels do not cause serious blood loss. The genetic disorder hereditary hemorrhagic telangiectasia Hereditary Hemorrhagic Telangiectasia (HHT) Hereditary hemorrhagic telangiectasia is a hereditary disorder in which blood vessels are malformed, making them fragile and prone to bleeding. Dilated blood vessels (telangiectasia) are present... read more is an exception.
Abnormalities of collagen in the blood vessels may occur in scurvy Vitamin C Deficiency In countries with low rates of food insecurity, vitamin C deficiency can occur from a diet low in vitamin C, but severe deficiency (causing scurvy) is uncommon. Not eating enough fresh fruits... read more (due to lack of vitamin C in the diet) and in Ehlers-Danlos syndrome Ehlers-Danlos Syndromes Ehlers-Danlos syndromes are rare hereditary disorders of connective tissue that result in unusually flexible joints, very elastic skin, and fragile tissues. These syndromes are caused by a defect... read more and other rare hereditary connective tissue disorders, including Marfan syndrome Marfan Syndrome Marfan syndrome is a rare hereditary disorder of connective tissue, resulting in abnormalities of the eyes, bones, heart, blood vessels, lungs, and central nervous system. This syndrome is caused... read more , osteogenesis imperfecta Osteogenesis Imperfecta Osteogenesis imperfecta is a hereditary disorder that disrupts the proper formation of bones and makes bones abnormally fragile. This disorder is caused by mutations in certain genes. Typical... read more , and pseudoxanthoma elasticum Pseudoxanthoma Elasticum Pseudoxanthoma elasticum is a rare hereditary disorder of connective tissue that causes abnormalities in the skin, eyes, and blood vessels. Connective tissue is the tough, often fibrous tissue... read more , leading to an increased risk of bleeding in these disorders.
Blood vessels can also be weakened by deposits of abnormal proteins in their walls Protein Disorders Causing Bruising or Bleeding Conditions that cause an abnormal protein or an abnormal amount of certain normal proteins in the blood can cause blood vessels to become fragile. When these fragile blood vessels break, people... read more as occurs in amyloidosis Amyloidosis Amyloidosis is a rare disease in which abnormally folded proteins form amyloid fibrils that accumulate in various tissues and organs, sometimes leading to organ dysfunction, organ failure, and... read more , cryoglobulinemia Cryoglobulinemia Conditions that cause an abnormal protein or an abnormal amount of certain normal proteins in the blood can cause blood vessels to become fragile. When these fragile blood vessels break, people... read more , and hypergammaglobulinemic purpura Hypergammaglobulinemic purpura Conditions that cause an abnormal protein or an abnormal amount of certain normal proteins in the blood can cause blood vessels to become fragile. When these fragile blood vessels break, people... read more , or by inflammation as in autoimmune vasculitis. For example, bleeding may be a prominent feature of immunoglobulin A–associated vasculitis Immunoglobulin A–Associated Vasculitis Immunoglobulin A–associated vasculitis (formerly called Henoch-Schönlein purpura) is inflammation of mainly small blood vessels that most often occurs in children. A rash of reddish purple bumps... read more , an inflammation of small blood vessels that is common during childhood.