Saliva testing, usually in the oral cavity, can detect the following diseases: first, it will detect Candida infection, because in saliva if there are excessive Candida mycelia, it can be determined that the patient has Candida albicans. Second, saliva can be tested for other staphylococci that exceed the standard, and can also assist in the diagnosis of inflammation of the parotid or sublingual glands. Third, saliva can be tested for the presence of Mycobacterium tuberculosis by sputum culture. The examination of saliva can also be combined with the examination of salivary glands. The examination of salivary glands can be excised for pathological diagnosis, and if there is lymphocytic infiltration in salivary glands, it proves that the patient may suffer from Schegren’s syndrome.