Sleeping and drooling with a putrid odor may be the odor produced by the tongue or periodontitis, as follows. 1. Tongue moss: the back of the tongue is a dense bacteria in the oral cavity, food debris and shedding cells retained on the back of the tongue become the substrate for bacterial degradation, which is the main source of oral odor. 2. Periodontitis: deep periodontal pockets of Porphyromonas gingivalis and Porphyromonas intermedia have a strong ability to produce odor, and the tongue of patients with periodontitis is usually more than those without periodontitis, saliva has a putrid smell may be caused by periodontitis and tongue together. Sleeping and drooling with putrid odor may have other reasons, if the putrid odor is serious or other symptoms, it is recommended to go to the hospital in a timely manner, with the help of the doctor to clarify the cause of the disease after targeted treatment.