Waking up in the morning with yellow saliva is dirty and even blood, the possible clinical causes are pharyngitis, tonsillitis, oral diseases, and so on. 1. pharyngitis: this situation is mostly seen in acute or chronic pharyngitis, the people with the clinical manifestations of sore throat, dry mouth, dry throat, yellow saliva, etc., if there is a rupture of the mucous membrane of the pharynx, there will also be the symptom of blood in the saliva. It is recommended that people with the disease should drink more water and reduce the consumption of spicy and stimulating food, and consult a doctor in time. 2. Tonsillitis: People suffering from purulent tonsillitis or acute tonsillitis will secrete inflammatory or purulent substances in the mouth, and the saliva will appear yellow. If there is also rupture of mucosal blood vessels, it will also lead to saliva with blood. 3. Oral diseases: clinically common such diseases are periodontitis, gingivitis, etc., the blind pocket of the gums are easy to harbor bacteria, which makes the saliva yellow and dirty. Infection can also cause the small blood vessels under the periodontal mucosa to swell, rupture or bleed, thus making the saliva bloody. These conditions are usually indicative of severe oral inflammation and need to be treated promptly. These are just some of the common causes. If the symptoms of yellowish saliva with blood persist, it is recommended to consult a doctor as soon as possible for a definitive diagnosis and standardized treatment.