The full name of hereditary capillary dilatation is hereditary hemorrhagic capillary dilatation, which is an autosomal dominant, hereditary, vascular disease that is characterized by dilation of capillaries in multiple areas of the skin and mucous membranes, and may lead to nosebleeds or other bleeding symptoms. The main cause of the disease is genetic, and it occurs in people with a family history of hereditary capillary dilatation. Dilated capillaries are usually concentrated in the skin of the face, lips, tongue, nail beds, palms, nasal cavity, etc. Capillaries 1~3 mm in size can be seen in the form of spots, spider-like, etc., and will appear to fade when pressed. If the patient’s nose bleeds repeatedly or there are symptoms such as hematuria, black stools, and purplish or bright red capillaries on the surface of the skin, it is recommended to go to the hospital in time. It is usually necessary to correct anemia and control bleeding to avoid serious complications.