Pharyngitis may result in coughing up blood, but usually this coughing up of blood is manifested as a small amount of blood in the sputum and usually not a large amount of blood. Patients may experience congestion and swelling of the local mucous membrane and submucous tissue due to acute and chronic inflammatory factors in the throat, and there may also be local vasodilation. After the stimulation of throat clearing or coughing, a small amount of local mucous membrane and submucous membrane blood vessels may break down and ooze blood, resulting in the appearance of blood in sputum. If a patient has a large amount of coughing blood with repeated episodes, a careful and comprehensive examination of the entire respiratory and digestive tracts is needed to investigate all possible causes.