The condition of pharyngitis, including acute pharyngitis and chronic pharyngitis, may lead to a small amount of bleeding in the mucous membrane of the throat, which may manifest itself as repeated blood in the sputum, often more obvious in the morning. Inflammation in the throat may lead to acute and chronic congestion and swelling of the local mucous membrane, and the blood vessels under the mucous membrane are often dilated, and the local mucous membrane may further break down and exude a small amount of blood. The accumulation of more blood will result in obvious blood in sputum and even the formation of obvious blood clot material. However, for patients with repeated blood in sputum symptoms, careful and thorough examination of the entire nasal cavity, sinuses, nasopharynx, pharynx and lower respiratory tract is required.