Thickening of the mucosa of the left maxillary sinus may be left maxillary sinusitis, which can occur at any age, with a higher incidence in adolescents, and is mostly due to prolonged colds that don’t go away. Patients may present with headache, nausea, vomiting, or they may have nasal congestion and runny nose, or they may have olfactory disturbances. It is mainly treated by applying antimicrobial drugs in the acute stage, and commonly used drugs include cephalosporin antibiotics, mainly ceftriaxone sodium, cefoperazone sulbactam, and also tinidazole, metronidazole or ornidazole can be applied for treatment. If the patient is not cured for a long time, it may cause chronic maxillary sinusitis, and the patient may also suffer from memory loss, inattention and disordered thinking, if necessary, can be carried out to improve the brain metabolism treatment, commonly used drugs are olanzapine, piracetam and cytarabine, but also can be carried out puncture irrigation treatment, so the patient must be treated in time after the cold.