Some causes can be lip biting, lip sucking, Vit.B2 deficiency, smoking, overexposure to sun and ill fiting dentures.Do not keep your lips dry, apply lip balm which contains sunscreen. If you have cracks at the corner of your mouth it indicates B2 deficiency in this case you need to take B2 supplements.A good home remedy to regain your natural lip color is rubbing a slice of lemon on your lip.You can try it out. Good luck!
My bottom lip is very discolored at first it just tingle then get swollen after it goes down my lip turns darker originally my lip is pink but after this started happening it hasn't changed. Also underneath my bottom lip is black as well I've had this problem for about a year now and it just seems like I cannot find an answer