Children about 1-7 years old have the disease, but most of them are children who are 15 years old, male to female ratio is 2:1 adults. Symptoms depend on the degree of pulmonary hemorrhage. Chronic bleeding may have mild persistent dry cough, fatigue, pale skin, weight loss and even clubbing. There may be blood in the sputum, dry cough, fatigue, pale skin, weight loss. In the latter period, the patient may have difficulty breathing, and even heart failure performance. In the acute phase and secondary infection, the patient has obvious smell and moist rales. Stool OB appears positive. X-rays have blotchy shadows. When pulmonary bleeding stops, shadow absorbs better in a few weeks.