Hello. I am a 28-year-old and I have within the past 3 weeks noticed that my lips are getting darker - a purplish/greyish color. This has happened before about 3 years ago and went away on its own. However it is happening again and I m not sure what s causing it. Iron deficiency, vitamin B deficiency, could be due to smoking, even heart disease/lung disease. Have you heard of this before? I m not in pain and my lips are smooth, they are just discolored. I have made an appointment at a local dermatologist for tomorrow, but I d just like to get some advice now on what it might be. Thanks!