Patients with a bad smell inside the nose mainly consider the following reasons: First, patients with diabetes are prone to diabetic ketoacidosis if their blood sugar is too high. There will be an abnormal smell inside the patient’s nose, and the patient’s blood sugar must be actively controlled. The second, mainly consider the patient’s nasal cavity inside a foreign body, will be accompanied by one side of the nose inside the flow of yellow pus nasal discharge, the odor is particularly obvious. It is recommended that the patient go to the hospital for active examination and removal of the foreign body. Thirdly, the patient may have polyps in the nose or sinusitis, which often leads to nasal anaerobic infection. No matter what the cause of the odor inside the nose, patients must be actively examined and treated symptomatically.