Common causes of white lips include pityriasis versicolor, vitiligo, sebaceous ectasia, and thrush. 1. simple furuncle: the etiology of this disease is unknown, may be associated with Malassezia furfur infection, intestinal parasitic infection, malnutrition, dry skin and other factors, occurring around the mouth, round or oval hypopigmented spots, size is not certain, after sun exposure is more pronounced and other symptoms. 2. vitiligo: the cause of this disease is unknown, may be related to autoimmune disease, oxidative stress, melanocyte self-destruction, heredity, neurochemical factors, etc., can occur in the mouth and lips, manifested in the skin and mucous membranes, round, oval white patches and other symptoms. 3. Sebaceous gland ectasia: the etiology of this disease is unknown, may be related to heredity, endocrine disorders, local stimulation, skin trauma and other factors, most commonly found in the oral mucosa, lips, manifested as a white papule or yellowish-white patches and other symptoms. 4. Thrush: this disease is mainly caused by low immunity, long-term use of glucocorticoids, diabetes, oral cleaning is not in place and other factors, manifested as scattered white milk clot-like dots or small pieces on the lips, gradually fused into a large area and other symptoms. It is recommended that patients go to a regular hospital, after a clear diagnosis, follow the doctor’s instructions and reasonable treatment, to avoid delaying the condition.