There are many causes of bad breath, and different causes lead to different treatments and medications. Halitosis caused by oral diseases can be treated with gargles; halitosis caused by diabetic ketoacidosis requires the use of insulin and other medications. Some oral diseases, such as dental caries, gingivitis and other causes of bad breath, can be used as appropriate, chlorhexidine solution, lactic acid isacridine solution and other rinses, to a certain extent, can improve the symptoms of bad breath. Bad breath caused by oral diseases mainly needs to be treated by scaling or correcting bad restorations or bad orthodontic appliances. Gastritis, gastric ulcers and other digestive disorders can also cause bad breath, and medications such as bismuth pectin and aluminum hydroxide can be used to treat the primary disease in order to relieve the symptoms of bad breath. If bad breath is caused by diabetic ketoacidosis, insulin, metformin and other medications are needed to control blood sugar, and bad breath can be relieved or disappear. In addition, consumption of garlic, green onions and other stimulating foods, or smoking can also cause bad breath, need to adjust dietary habits, develop the habit of brushing teeth and gargling to maintain oral hygiene, can also improve the symptoms of bad breath. It is recommended that patients with bad breath should consult a doctor in time to clarify the cause of the disease and then carry out the treatment of the cause, and should not blindly use their own medication.