Darkening of the perioral area may be related to food staining, hyperpigmentation, hypoxia and cyanosis. It needs to be treated for the cause, mainly through medication and surgery. Consumption of food with high melanin content stains the perioral area, and failure to clean the perioral area can lead to perioral darkening, which can be treated by cleaning the perioral area with water. Post-inflammatory hyperpigmentation or medication hyperpigmentation can also lead to perioral blackening symptoms, common treatment drugs are hydroquinone, retinoic acid cream, corticosteroids and so on. It can also be treated with surgical laser therapy. Patients with hypoxemia can also lead to perioral darkening, which requires etiologic treatment. Associated diseases are tetralogy of Fallot and chronic obstructive pulmonary disease. Treatment includes oxygen, glucocorticosteroids in combination with long-acting β2-adrenoceptor agonists, and related surgical procedures such as subclavian artery-pulmonary artery bypass. If you find blackness around the mouth, you should consult a doctor and take different treatments according to the examination results for different causes under the guidance of the doctor, and you should not take medication without authorization to avoid delaying the condition. Pay attention to rest on weekdays and avoid overwork.