What Causes Black Spots On The Leg?

Dear Sir,

I am suffering from a problem last three month. There is three small spots of black colour in my right leg. First these spot was red colour . There is no pain or etach in these effected area.

but problem is this , is it a indication of any problem if yes , will you advise is it skin problem or other and how to remove it.

Thanks & Regards

Sandeep Agarwal

M-0000