Waking up in the morning with blood in the mouth is mainly considered to be oral diseases, nasopharyngeal diseases, digestive system diseases and blood system diseases. 1. Oral diseases: such as dental caries, chronic gingivitis and other diseases produced by repeated inflammatory stimulation can cause gum swelling, seepage of blood, thus causing the symptoms of waking up in the morning with blood in the mouth. 2. Nasopharyngeal diseases: such as nasopharyngeal inflammation, tumors, etc. can cause bleeding in the nasal cavity, the blood can flow into the mouth through the pharynx, the symptoms of waking up in the morning with blood in the mouth. 3. Digestive system diseases: such as peptic ulcer, acute erosive hemorrhagic gastritis, rupture of esophagogastric fundal varices, gastric cancer, etc. can cause upper gastrointestinal bleeding, which can flow into the oral cavity, thus waking up in the morning with the symptom of blood in the mouth. 4. Blood system diseases: such as thrombocytopenic purpura, leukemia, etc. can cause coagulation dysfunction, thrombocytopenia, which further causes bleeding gums, can also be manifested as waking up in the morning with blood in the mouth. If you wake up in the morning with the symptom of blood in the mouth, it is recommended to consult a doctor in time, combined with the relevant symptoms and medical history to clarify the cause of the active treatment, so as not to delay the condition.