I have painful black spot on my skin. its not bulgy or contains water, just flat on the skin darkened and the area becomes painful?

Nevis: It sounds like a mole or Nevus and if it is painful may need to be removed. See you doctor for an exam and an opinion. All the best.

See dermatologist: Hi. I can't tell from the description, but it sounds like it should be seen by a dermatologist.

Dark skin lesion: requires a comprehensive dermatological evaluation and possibly a biopsy- do not ignore.

Dermatologic: evaluation is the only way to correctly identify this lesion & if any course of action is indicated. Take care.