Hemangioma Say: he-man-jee-oh-muh This is a big word for a type of birthmark. Birthmarks get their name because they develop on the skin of babies before or just after they are born. Hemangiomas are a bunch of tiny blood vessels – that's why they usually look red or purple. These birthmarks can be very small or quite large and tend to get bigger before they get better. Hemangiomas don't hurt and usually go away on their own in a couple of years. Back to Articles Related Articles Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.