The common causes of saliva thick like phlegm are too many dental calculus, inflammation of salivary glands, poor gastrointestinal function and so on. Patients should go to the regular hospital in time, under the guidance of professional doctors for symptomatic treatment. 1. Too many dental calculus: If the patient’s saliva is thick like phlegm, and at the same time there are symptoms of halitosis, the first thing to consider is the possibility of too many dental calculus. Too much calculus will cause plaque to increase, the gingival sulcus secretion also increases, the saliva will be sticky like phlegm, but also produce bad breath. 2. Inflammation of salivary glands: When salivary glands are inflamed, a large amount of secretion will remain in the mouth, and the amount of saliva will be reduced, which will lead to sticky saliva like phlegm. 3. Poor gastrointestinal function: If the patient has poor gastrointestinal function for a long time, it will lead to gastroesophageal reflux, which will make the saliva sticky like phlegm. If the saliva is sticky and accompanied by discomfort, go to the hospital.