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Facts at a Glance
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  1. Approximately 1.2 million people world-wide have Hereditary Hemorrhagic Telangiectasia (HHT). HHT is uncommon, but not rare.
  2. Symptoms can be mild to severe.
  3. Physicians frequently miss (do not make) the diagnosis in affected individuals.
  4. Most commonly affected organs are the nose, lungs, GI tract, brain, and spine-in that order.
  5. Abnormally formed blood vessels (telangiectasia and arteriovenous malformations) cause all the symptoms of HHT.
  6. 90-95% of individuals with HHT will have nosebleeds by adulthood, but they vary from infrequent and minor to daily and severe.
  7. 90-95% develop at least a few telangiectasia (small red or purple spots) on the skin of the face and/or hands by middle age.
  8. 20-25% develop bleeding in the stomach or intestines, but rarely before 50.
  9. 30-50% have an arteriovenous malformation (AVM) in their lungs. These are usually present at birth.
  10. 5-20% have an AVM in their brain. These are present at birth.
  11. Brain and lung AVMs should be detected and treated before they cause a problem. Brain and lung AVMs exist as “hidden time bombs” in HHT patients.
  12. Abnormal blood vessels in the liver are relatively common, but most cause no symptoms. Biopsy or treatment should rarely be done and specifically, embolization should not be done. Liver AVMs are not time bombs like the brain and lung AVM.
  13. It is extremely rare for any one individual to have all the manifestations of HHT.
  14. The severity of one’s nosebleeds does not predict the likelihood to have internal (i.e. brain and lung) manifestations.
  15. Severity of the disorder varies tremendously, even between close relatives.
  16. Treatments are available for all manifestations of HHT
  17. HHT is a hereditary disorder. Defects in at least 3 genes are known to cause HHT, but only one gene is the cause in any one family.
  18. Men and women are affected with HHT in equal numbers.
  19. The HHT Foundation recommends that people with HHT be assessed at a specialized HHT Center at least once as early in life as possible. Diagnosis and treatment for HHT is complex and has changed significantly in the last decade.