Definition of HHT

HHT in figures



Of individuals with HHT will have nosebleeds by adulthood, but severity varies from infrequent and minor to daily and severe.



Develop at least a few telangiectases (small red or purple spots) on the skin of the face and/or hands by middle age.

Gastro-intestinal bleeding


Develop significant gastric or intestinal bleeding, but rarely before 50 years of age unless affected with juvenile polyposis in conjunction with HHT.

Lungs AVMs


Have lung AVMs. These pose significant risk.

Brain AVMs


Have at least one brain AVM. These can be present at any time in life, even at birth, and can cause serious complications. Routine screening is recommended.

Liver AVMs


Liver AVMs are relatively common, but only approximately 10% cause symptoms.

Abnormal blood vessels in the liver are relatively common. Most cause no symptoms, however high cardiac output resulting in possible cardiac failure has been linked to liver HHT. Biopsy or treatment should rarely be done; specifically, embolisation should not be done.

Document for your doctor

Should your doctor not understand HHT, we recommend you download the following fact sheet and bring with you to your next visit.

This document offers a quick view of the most common facts of HHT.

Download the fact sheet here: Fact-Sheet-2020

HHT FactSheet