Hereditary hemorrhagic telangiectasia (HHT) is an inherited disorder of the blood vessels that can cause excessive bleeding. People with HHT can develop abnormal blood vessels called arteriovenous malformations (AVMs) in several areas of the body. AVMs on the skin are called telangiectasias.AVMs can also develop in other parts of the body, including the brain, lungs, liver, or intestines.
https://rarediseases.info.nih.gov/diseases/6626/hereditary-hemorrhagic-telangiectasia