Maybe there's something wrong with the digestive system. If there is pigmentation on the edge of the lips, it may be renal insufficiency; Black and purple lips are obvious symptoms of blood hypoxia. Other symptoms may also occur, such as pneumonia, heart failure, asthma, cor pulmonale, constipation, abdominal pain and diarrhea.

There are many reasons for black lips, so we should not be careless. You should ask a doctor to check, find out the exact cause and treat it in time.

Allergy to anti-inflammatory drugs can also cause lips to turn black. Eating phosphoformic acid will turn black, and it will take more than half a year to change back.

Don't be careless when your lips are black. Go to the clinic at once. See the cardiovascular department first!

I suggest you go to at least a tertiary first-class hospital.

You should add some other symptoms, such as your feeling after doing some strenuous activities, your sleep situation, and your eating characteristics. Has anyone in your family ever suffered from cardiovascular disease? How old are you this year? When did you find yourself with this symptom? Wait a minute. These can all be caused!