Dark spots on lips may be pigmented nevus, hyperpigmentation, intestinal polyp syndrome, fixed drug rash. 1. pigmented nevus: lips can grow pigmented nevus, the pigmented nevus on lips should be cut off as soon as possible and do pathological examination to determine the benign and malignant. 2. Hyperpigmentation: after 40 years old, there will be hyperpigmentation on the lips, which is a normal phenomenon without special treatment. If you think it affects your beauty, you can go to the hospital to get rid of the pigment by laser. 3. Intestinal polyp syndrome: there are polyps in the small intestine, and at the same time, there is hyperpigmentation on the lips. If accompanied by abdominal pain, black stool symptoms, please seek medical attention as soon as possible. If the presence of polyps is found after colonoscopy they can be removed. 4. Fixed drug rash: some people often take medication, after taking medication, lip redness, swelling, itching and other symptoms, after the lesions subside, there can be hyperpigmentation, appeared in a fixed position, for fixed drug rash. Treatment needs to stop using the suspected drugs, and the black spots can disappear after stopping the drugs for several months. To summarize, dark spots on the lips can go to the hospital, clarify the cause of the disease, and follow the doctor’s instructions for treatment.