Bad breath is the foul odor emanating from the mouth or other air-filled cavities. Treatment policy: identify the cause and enhance oral hygiene for symptomatic treatment. First, choose the correct brushing method, brush your teeth at least twice a day, and develop the habit of rinsing your mouth after eating. Second, the tongue clean or choose energy-efficient inhibition of the growth of microorganisms on the tongue mouthwash, local antibacterial. Third, chewing fiber-rich food or chewing gum is conducive to reducing bad breath. Fourth, stimulate saliva secretion or use alternatives to clean the mouth. Daily care pay attention to oral hygiene, with oral local factors, remove oral lesions, use mouthwash, brush and rinse carefully every morning, before bed and after meals. Gently brush away the tongue with a toothbrush or clean towel when necessary. Eat a relatively light diet, avoid eating raw and cold, irritating with foul odor, such as onion, ginger, garlic, leek, stinky tofu and other and indigestible greasy food, chew slowly when eating, drink more water, eat more vegetables and fruits and legumes.