Daily work often hear people complain about their bad breath, now from a medical point of view to analyze, I hope to help you a little. Normal people in the mouth or speech breathing almost all have a certain smell, especially after eating garlic, onions, leeks, lamb, stinky tofu and other foods, the corresponding smell in the mouth will be more obvious, these abnormal odors can be eliminated or reduced by brushing teeth, rinsing, this one-off also known as food-borne halitosis believe that the vast majority of people have experienced, not surprising. True halitosis, also known as bad breath, is the exclusion of the above causes, the persistent appearance of the unpleasant odor emanating from the mouth to annoy others and embarrass themselves. Bad breath is a small thing, the impact can be large; it may not only be a signal of serious diseases, but also to people’s normal interpersonal communication and life brings low self-esteem and embarrassment. There are sources of bad breath due to unclean mouth, food residues by bacterial decay and fermentation of the sour smell. There are also a variety of oral diseases such as periodontitis, dry socket, necrotizing stomatitis and even oral tumors, resulting in tissue exudation, bleeding, ulceration, necrosis and bacterial infection and corruption of the putrid smell, bloody smell; various nasopharyngeal diseases such as atrophic rhinitis, paranasal sinusitis, purulent tonsillitis, nasopharyngeal carcinoma, etc. resulting in pus dripping from the posterior nostril, exudation, bleeding and necrosis, the smell of pus, bloody smell. Digestive system diseases such as Helicobacter pylori infection, indigestion, constipation, digestive tract obstruction, especially pancreatic cancer and gastric cancer combined with pyloric obstruction, chronic liver disease, especially cirrhosis, liver necrosis of severe hepatitis, etc. produce rancid smell, fecal odor or liver odor; respiratory system diseases such as lung abscess patients often appear putrid odor, pulmonary tuberculosis, bronchial dilatation hemoptysis often appear bloody odor, lung cancer patients often in the mouth and in the exhaled breath Patients with lung cancer often have a putrid odor in their mouth and breath. Hematologic diseases such as leukemia, thrombocytopenic purpura, granulocyte deficiency, etc. lead to bleeding gums, infection and blood odor; metabolic diseases such as diabetic ketoacidosis, the smell of rotten pimples exhaled from the mouth and nose; urine odor in patients with uremia; lead, mercury and other heavy metal poisoning patients appear in the mouth metal odor. For food-borne halitosis, smoker’s smoke odor as long as you develop good habits such as rinsing your mouth after meals, brushing your teeth in the morning and evening; eating a light diet, less spicy, meals are not full (especially dinner); keep your bowels open; quit smoking and alcohol, etc., bad breath can be removed. For the above-mentioned diseases of halitosis, only the corresponding treatment for the original disease is possible to remove bad breath. Chew more gum in ordinary life, or use breath freshener; gargle with light salt water after meals, can sterilize and anti-inflammatory; chew cilantro, tea or peanut rice, can make its unique aroma fully emitted, purify breath; add some mint or fresh lemon juice in milk or boiled water to drink to remove odor; eat tomatoes, grapefruit, dates, oranges can also help eliminate bad breath.