The common causes of yellowish blood in the morning spit are oral diseases such as gingivitis, periodontitis, and other causes such as sinusitis, etc. The most common causes of yellowish blood in the morning spit are oral diseases such as gingivitis and periodontitis. 1. If there is gingivitis, periodontitis, there will be the phenomenon that the gums bleed easily, and thus the phenomenon of yellowish saliva with blood in the morning will occur. Often caused by not paying attention to oral hygiene, too much calculus. If gingivitis is present, scaling is usually all that is needed. If periodontitis exists, periodontal systemic treatment is needed, including scaling and subgingival scraping. 2. In addition, if there are nasopharyngeal diseases such as sinusitis, there will also be the phenomenon of blood in the saliva, generally need to carry out the corresponding drug treatment. If there is blood in the saliva in the morning, go to the hospital in time for examination and treatment.