Blackened lips may be caused by physiological reasons such as overwork, or by hepatitis, kidney dysfunction and heart failure. 1. Overwork: Long-term irregular rest, excessive mental load and lack of sleep can lead to an increase in melanin in the lips, resulting in the symptom of blackened lips. 2. Hepatitis: blackened lips are usually caused by decreased liver function and increased melanin production. 3. Kidney dysfunction: when kidney dysfunction occurs, it will be accompanied by pigmentation around the lips, thus causing the phenomenon of black lips. 4. Heart failure: when the patient suffers from heart failure, it will cause the phenomenon of hypoxia, which will lead to the phenomenon of blackened lips. When the patient has a black lip, should go to the hospital in time to consult, clear cause actively cooperate with the doctor’s treatment.