What is Hereditary Hemorrhagic Telangiectasia? Hereditary Hemorrhagic Telangiectasia (HHT) an autosomal dominant disorder of the blood vessels characterized by recurrent nosebleeds, spider-like blood vessels, and arteriovenous malformations (AVMs). Learn more by hovering over the interactive image and watching our short video reviews. Study smarter with Pixorize. Retain more, gain a deeper understanding, and feel more prepared for your clerkships and the USMLE STEP 1/NBME shelf exams. Get early access to our upcoming releases, giveaways, and more by following us on social media!