Drooling in men’s sleep may be a normal phenomenon, or it may be caused by localized inflammation in the mouth, or it may be caused by nerve disorders. 1. Normal phenomenon: due to the salivary glands in the mouth will continue to secrete saliva, when men lie on their sides, lying on their stomachs to sleep, or sleep with their mouths open, there will be drooling. 2. Localized inflammation of the oral cavity: due to poor hygiene in the oral cavity, such as teeth brushing is not clean, plaque breeding, a large number of caries in the oral cavity, the mouth of the dental calculus, stimulating and destroying the mucous membrane in the oral cavity, which leads to the occurrence of inflammation of the oral cavity. In turn, there is an increase in secretions, and men will experience drooling in their sleep. 3. Nerve abnormality: it will lead to increased saliva, more obvious at night, thus drooling while sleeping. The nerves have direct control over the muscles. When the nerves related to swallowing are abnormal, it will affect the muscle activity, thus affecting the swallowing function and leading to drooling during sleep. If men still experience drooling in their sleep after changing their sleeping position, they should go to the hospital in time to be examined, to clarify the cause of the disease, and to take timely treatment measures.