The common reasons for the phenomenon of bleeding with phlegm in the throat when brushing teeth are as follows: 1. To exclude gum bleeding, gum bleeding can lead to phlegm in the throat accompanied by bleeding when brushing teeth, but as long as there is phlegm, it means that there is still some inflammation in the throat, so that the phenomenon of phlegm accompanied by bleeding can occur. At this time, if there is inflammation in the throat, there will be congestion and edema, and also secretion of inflammatory secretions, which will form phlegm, and if accompanied by the exudation of blood cells, there will also be symptoms of phlegm with bleeding; 2. In addition, a relatively rare cause is the occurrence of tuberculosis, which will lead to the phenomenon of phlegm with bleeding in the throat, because the tuberculosis bacillus can easily invade small blood vessels leading to the symptoms of bleeding. 3. Tumors in the lungs may also lead to phlegm The symptom of bleeding is because the tumor easily invades the blood vessels. When bronchial dilatation occurs, a large amount of phlegm will accumulate in the dilated bronchi; 4. In addition, there are some blood vessels that rupture because of bronchial dilatation, and the symptom of bleeding with phlegm will appear.