The causes of dark lips include digestive disorders, heart disease, tetralogy of Fallot, etc. It is recommended to treat the cause of the disease, and commonly used methods include medication and surgery. 1. Digestive system disorders: When the digestive system functions abnormally, toxic substances will gradually accumulate in the body, which in turn manifests the phenomenon of black lips. For this situation, you can take drugs such as Trimethoprim, Mosapride and Domperidone tablets under the guidance of healthcare professionals to promote gastric power. 2. Heart disease: This is mainly because heart disease affects the blood circulation in the body, which in turn leads to lack of oxygen, resulting in blackness around the lips. Generally speaking, due to heart disease caused by black lips around can be in the physician’s guidance to take nitroglycerin, isosorbide nitrate to dilate blood vessels, at the same time with lidocaine, aspirin, heparin and other drugs to treat. If necessary, you also need to eliminate the disease through surgery, common percutaneous coronary intervention, defect blockage, radiofrequency ablation and so on. 3. Tetralogy of Fallot: Tetralogy of Fallot is a congenital disease that leads to cardiovascular malformations, causing the patient to suffer from oxygen deprivation and blackening around the lips. The main treatment for tetralogy of Fallot is surgery, such as tetralogy of Fallot correction, palliative surgery and so on. Many factors in life can cause darkening around the lips and it is advisable to seek early medical attention to avoid worsening of the condition.