We will collect and save information from your medical record, including things like your diagnosis, age, sex, race, symptoms, HHT genetic results, organ involvement, and your general health. We will review and save images, including X-rays, CTs, angiograms, and MRIs. We will ask you study-related questions in clinic or have you fill out a questionnaire about your demographics, past and current medical history, and behavioral history (e.g., recreational drug use, smoking, etc.). We will also have you fill out a quality of life survey. We will ask you questions about your family history so we can draw a family tree. A family tree is a picture that shows how family members are related. We will ask you their names, dates of birth, relationship to you, and about their health. This will take 30-45 minutes. If there is any missing information, we would like to be able to call you. Every 1 to 2 years after enrollment, for up to 10 years or until the study ends, you will be contacted to update information regarding any treatment and complications of HHT. This call will take about 15 minutes. In addition to your collecting your health information, you may also choose to agree to let researchers collect and store your specimens for research, we will collect a sample of blood, saliva, and/or tissue from you. The specimens will be labeled with a study ID number only and will not have any personal identifiers on them.