Rhinorrhea is the most common clinical manifestation of HHT, appearing earliest, with its first onset at a mean age of approximately 12 years. Rhinorrhea is mostly spontaneous or induced by mild irritation and occurs more frequently at night. Symptoms of rhinorrhea may be mild in the early stages; they become progressively worse in the later stages. Most patients present with multiple capillary dilation of the skin and mucous membranes, seen on the face, lips, tongue, conjunctiva, trunk, and fingers. It usually appears around 30 to 40 years of age. Pulmonary arteriovenous malformations occur in 30% of patients with HHT. Arteriovenous malformations of the lungs are congenital and increase in size as the body grows. Most patients have no obvious symptoms for many years, while others develop severe or sudden dyspnea, cyanosis of the lips and mouth, and hemoptysis. Strokes, transient cerebral ischemia, and brain abscesses caused by these malformations may lead to serious consequences. Gastrointestinal bleeding occurs in 25% to 33% of patients with HHT, with an average age of onset of 57 years, mostly in the gastroduodenum, and manifests as black or dark red blood in the stool. The black solids indicate patients, and the arrows point to the first evidence (the first patient identified). This is a family tree of HHT patients. HHT is a hereditary disease with a family history. Clinical diagnostic criteria for HHT If, the diagnosis of HHT patient can be confirmed; if the above 2 criteria are met, the patient may be HHT patient; if only 1 criterion is met, the diagnosis of HHT can be excluded. Diagnosis and treatment process for HHT patients