HHT Foundation International

Hereditary Hemorrhagic Telangiectasia (HHT) is a genetic disorder of the blood vessels, which affects approximately 1 in 5,000 people. It affects males and females from all racial and ethnic groups. The disorder is also sometimes referred to as Osler-Weber-Rendu (OWR) after several doctors who studied HHT about 100 years ago. In 1896 Dr. Rendu first described HHT as a hereditary disorder involving nosebleeds and characteristic red spots that was distinctly different from hemophilia.

Before Dr. Rendu's work, doctors did not understand that individuals with what we now call HHT have abnormalities of their blood vessels, not a clotting problem in the blood itself. Drs. Weber and Osler reported on additional features of HHT in the early 1900s. More than one hundred years later, HHT is still often misdiagnosed in affected individuals and many doctors do not understand all of its manifestations.