Coughing is a very common protective reflex action in the human body, such as airway irritation from smoking, choking with odor, and also one of the common symptoms of respiratory diseases, such as bronchitis, pneumonia, and lung cancer. In contrast, blood in sputum, which is medically classified as hemoptysis, is not common, so it is very worrying and frightening to have hemoptysis or blood in sputum, and will be unnaturally associated with lung cancer. Here’s how to understand what blood in sputum is all about! What is blood in sputum? Medically, blood in sputum refers to the mixing of bright red blood in sputum to a small amount of hemoptysis, which is bleeding from the throat and the following respiratory tract through the mouth. Therefore, bleeding in the mouth mixed with sputum or blood vomited mixed with sputum cannot be considered blood in sputum. What are the causes of blood in sputum? There are many causes of blood in sputum, and according to the source of bleeding, the common ones are as follows: 1. Bleeding caused by throat diseases The throat belongs to the upper respiratory tract, and the mucous membrane is fragile and rich in capillaries. When there is inflammation, foreign body piercing (fish spike, bone spike, etc.) and pharyngeal tumors (such as nasopharyngeal carcinoma), small blood vessels expand, the permeability of the blood vessel wall is enhanced, and under the stimulation of inflammation and violent coughing, it is easy to rupture and bleed and cough out through the mouth. In general, pharyngitis is not easy to bleed, and even if it does, the amount is very small. In older people, if there is blood in the sputum, especially if it is accompanied by bleeding in the nose, there is a possibility of nasopharyngeal cancer, which must be paid attention to. 2. Bleeding caused by lower respiratory tract diseases When the vocal cords are closed, the lower respiratory tract is in a closed state, and bleeding from ruptured blood vessels in the airway is mostly caused by lesions. Therefore, hemoptysis mostly indicates lesions in the trachea, bronchi and lungs. There are three common causes: tuberculosis, bronchiectasis, and lung cancer. In China, the primary cause is tuberculosis, followed by bronchiectasis and lung cancer. In young people with blood in sputum, if accompanied by cough, night sweats and wasting, tuberculosis is mostly considered; in older people, lung cancer is more likely, especially in those with irritating cough and a long history of smoking. In the elderly, lung cancer is more likely, especially in those with an irritating cough and a long history of smoking. In addition, pneumonia and bronchitis also have the phenomenon of blood in sputum. Chronic bronchitis and mycoplasma pneumonia may also have blood in sputum, but the amount is usually small. 3, bleeding caused by cardiovascular disease The cardiovascular system is closely related to the pulmonary circulatory system, and when cardiovascular disease occurs, it can often cause pulmonary stasis and rupture of bronchial capillaries. Mostly seen in mitral stenosis, followed by pulmonary hypertension due to precordial disease, and pulmonary embolism, pulmonary vasculitis, hypertension, etc. can also cause blood in the sputum or hemoptysis. These are mostly accompanied by a long-term history of cardiovascular disease, and their hemoptysis symptoms are small in volume, with pink foamy sputum, and generally do not need to panic, and can disappear when cardiovascular disease is controlled. 4. Bleeding caused by systemic diseases Hematological diseases such as leukemia and hemophilia cause bleeding due to abnormal coagulation function and easy rupture of airway mucosa, and there are also some immune diseases such as systemic lupus erythematosus and Wegener’s granulomatosis. As can be seen, there are many diseases that cause blood in sputum, both from the upper respiratory tract and lower respiratory tract, as well as from several other systemic diseases. Therefore, when blood in sputum appears, it is not necessary to be overly afraid, nor should it be taken lightly or lightly. It is necessary to make the corresponding choice of consultation in combination with other accompanying symptoms of oneself, and to pay high attention to early medical consultation, early examination, early detection and early treatment.