There are several different types of birthmarks; the most common are either vascular birthmarks which are red or purple, or pigmented birthmarks which usually appear in varying shades of brown. Most birthmarks are harmless, but if prominent or enlarging you may wish to have them removed for cosmetic reasons.
Some vascular lesions tend to regress themselves with time although persistence may necessitate laser therapy or surgical excision. If you have a congenital melanocytic naevi (CMN), it can be removed by surgery and then the edges of the skin are stitched together leaving a linear scar less obvious than the original lesion. If the area is large then you may need excision in stages or use of a skin graft or local flap of skin to cover the wound.