A vascular nevus is a type of birthmark that appears on the skin as a result of an overgrowth of blood vessels. Synonyms for vascular nevus include hemangioma, strawberry mark, and port-wine stain. Hemangioma is a type of vascular tumor that can be present at birth or develop shortly thereafter. A strawberry mark is a type of vascular nevus that appears as a bright red, raised, and rough-textured birthmark. Port-wine stain is another type of vascular nevus that appears as a dark red or purple birthmark that can be flat or raised. While these terms are often used interchangeably, they may refer to different variations of vascular birthmarks.