Structural Problems with Blood Vessels
Excessive bleeding and bruising may be the result of blood vessels that have not formed properly or do not function as they should. The following are a few examples:
- Hemorrhagic Telangiectasia – blood vessels are more fragile than usual, leading to recurrent bleeding episodes; this rare disease affects approximately 1 in 50,000 people.
- Ehlers-Danlos syndrome – collagen that supports blood vessels is unusually weak and elastic, making blood vessels less protected and more prone to injury; this disease affects 1 in 10,000 to 20,000 live births.
- Allergic purpura – small blood vessels are inflamed and prone to leakage, a condition thought to be an autoimmune response, and may be acute or chronic
- Infectious purpura – blood vessels may be damaged directly by microorganisms or by toxin produced by them; examples of causes include infections with Streptococcus or Staphylococcus bacteria, Rocky Mountain Spotted Fever, and malaria.
- Metabolic purpura – caused by a defect in metabolism; one example is vitamin C deficiency, also called scurvy. This condition results in small blood vessels that have weakened walls due to a defect in collagen synthesis. It is much less common now than it was a few hundred years ago but can still be seen in areas of extreme poverty or war.