Coughing up blood but no other symptoms may be related to bleeding gums, tuberculosis, lung cancer and so on. 1. Gum bleeding, generally no special conscious symptoms, due to bleeding gums can not be coughed up in time after bleeding, along with the sputum coughed up, manifested as coughing up blood. 2. Tuberculosis, coughing up blood is a typical symptom of tuberculosis, but in the early stage of the disease, only bleeding and coughing up blood may be accompanied by occasional low-grade fever, etc., and the conscious symptoms are not obvious. 3. Lung cancer is a typical disease that can cause coughing up blood, and at the same time, the early symptoms of the disease are relatively hidden. Tumors can cause local bleeding, and the blood is discharged with sputum, which leads to such symptoms. There may be other reasons for coughing up blood, if the symptoms are serious, you need to consult a regular hospital in time, and cooperate with the doctor to improve the examination and standardize the treatment.