The possible causes of dry mouth with blood in saliva at night are caused by drinking less water, open-mouth breathing, bleeding gums and inflammation of tonsils. 1. Drinking less water can cause the occurrence of dry mouth symptoms. Drinking less than the human body’s standard 2,000ml of water per day can cause oral salivary secretion to be sticky, resulting in dry mouth symptoms. Seasonal factors can also cause, for example, in the summer when there is high temperature can also cause dry mouth symptoms. At night, it is easier to have dry mouth with blood in the saliva. 2. Open-mouth breathing is mainly caused by nasal blockage and enlarged tonsils. Dry mouth symptoms caused by open-mouth breathing habits are common in pathological changes. Obesity caused by excessive can also cause cause mouth breathing, resulting in rapid evaporation of water in the mouth leading to dry mouth at night with blood in the saliva. 3. Gum bleeding due to oral dryness, dental calculus stimulation caused by more dental calculus, gums red and swollen will also cause bleeding occurs. Tonsil inflammation local mucosal congestion and edema, may cause dry mouth at night oral bleeding occurs. If there is a problem of dry mouth and bleeding gums at night, it is recommended to consult a doctor in time to rule out pathological problems.