What causes me to have black and blue spots on my lower lip?

Unusual: If you are on blood thinners, these could be bruises. They could also be venous lakes (essentially small varicose vein type lesions) or they cold be nevi (moles). It would be best to see a dermatologist or your physician for an evaluation.

Agree w Dr Placik: These lesions need to be visualized & a history needs to be obtained in order to make an accurate diagnosis. Sometimes lab testing or biopsy is necessary.