Most respiratory diseases have coughing and sputum symptoms. Sputum can be grayish-white mucus sputum or yellowish-green pus sputum, and sometimes coughing up sputum with bright red blood is called hemoptysis. In medicine, bleeding from the trachea, bronchus or lung tissue below the larynx that is expelled through coughing is called hemoptysis. Hemoptysis is a common clinical symptom that should be further identified as the primary disease causing hemoptysis, and many diseases can cause hemoptysis, mainly the following diseases for careful differential diagnosis: 1. The hemoptysis can be more than 500ml and the color of tuberculosis hemoptysis is bright red. 2, bronchiectasis Hemoptysis is a common symptom of bronchiectasis, the literature reports about 90% of patients with varying degrees of hemoptysis. A small number of mouths and a large number of mouths each time up to 500ml or more, bright red. 3.Lung cancer About 60% of primary lung cancer have hemoptysis symptoms, mostly blood in sputum or small amount of hemoptysis in persistent or phlegm intermittently, blood sputum and large hemoptysis are rare. This disease is mostly seen in elderly national patients, and about 20% of patients have bloody sputum as the first symptom. 4, lung abscess More rapid onset, with high fever, cough chest pain, spitting a lot of purulent sputum or purulent blood sputum, often a complication of pneumonia and staphylococcal sepsis, etc. About 50% of patients have hemoptysis symptoms, hemoptysis volume is not large. The course of the disease is about 2 weeks when coughing up a lot of pus sputum, the patient’s body temperature is also reduced, the lesion can be gradually absorbed, and the condition is improved and recently cured, and chronic lung abscess can be formed if it is not cured. 5, chronic bronchitis Chronic bronchitis also has hemoptysis, usually in small amounts or with blood in the sputum, as a result of bronchial mucous membrane congestion injury generally does not require treatment, within 3-4d stop on their own, but also easy to recur signs, X-ray and sputum examination is often no characteristic changes, chronic bronchitis patients with persistent small amounts of hemoptysis must be careful to find other causes, especially bronchial cancer, so as not to delay the diagnosis. 6. Pneumonia Most patients with acute pneumonia have an acute onset, with chills and high fever, coughing and chest pain, and hemoptysis, which is caused by a high degree of congestion in the lung parenchyma and increased permeability of small blood vessels and can rupture and cause hemoptysis. 7, pulmonary fungal disease, including Candida albicans, Aspergillus pneumoniae and new cryptococcosis, etc., usually with fever and weakness, cough, hemoptysis or purulent sputum is seen in the elderly, young children or frail malnourished patients, X-ray easily confused with septic pneumonia and tuberculosis good patients X-ray easily confused with septic pneumonia and tuberculosis, sputum found in straight bacteria or positive serum reaction can confirm the diagnosis. 8. pulmonary amebiasis One of the complications of hepatic amebiasis, which can also come from intestinal lesions. It usually has fever and weakness, cough and chest pain easily confused with chronic lung abscess and pulmonary tuberculosis. The typical sputum is brownish with a fishy odor X-ray reveals a patchy inflammatory or cavernous shadow in the lung, mostly in the right lower lung. Amoebic trophozoites can occasionally be found in the sputum. 9, pulmonary schistosomiasis This disease is strictly regional, mostly prevalent in Zhejiang, Fujian Sichuan and other areas. Patients all have a history of eating uncooked stone crabs or grubs in the disease area. The main clinical symptoms are cough and sputum, hemoptysis, chest pain typical sputum is rusty or brownish yellow. Although the patient has long-term recurrent hemoptysis, but the general condition is still good signs are not obvious, blood eosinophilia, X-ray can sometimes see infiltration cystic shadow or pleural effusion pleural thickening, etc., pulmonary schistosome intradermal antigen test positive or sputum found in the pulmonary schistosome eggs can confirm the diagnosis. 10, pulmonary encysticercosis is caused by the parasitic larvae of tapeworm larvae in human lungs, early asymptomatic, coughing and coughing, hemoptysis and chest pain when the cysts increase in combination with infection, X-ray can be seen in the lungs in a rounded ovoid, slightly lobulated shadow, cyst rupture air into the top of a half-moon shaped band This disease is prevalent in the northwest and Inner Mongolia region of China encyst antigen intradermal test and complement binding test is important for diagnosis. The intracutaneous test and complement binding test are important for diagnosis.