Birthmarks get their name for one simple reason: They are marks that are present on the skin of a lot of newborn babies! A baby can develop birthmarks either before being born or soon after birth.
One of the most common types of birthmarks is called a hemangioma (say: he-man-jee-o-muh). These birthmarks happen when many new blood vessels grow in a specific area on the skin. Blood vessels are tiny tubes that carry blood through the body.
No one knows what causes blood vessels to group together, but it's good to know that most birthmarks don't hurt at all and they usually aren't a sign of any kind of illness. Lots of newborns have these birthmarks on their bodies, like between the eyebrows (where they're called angel kisses). These birthmarks usually disappear within the first few months to years of life.
Types of Hemangiomas

One kind of hemangioma is called a strawberry hemangioma. If you think it gets its name from the fruit, you're right. A strawberry hemangioma is bright red and sticks out of the skin, so it does look a little bit like a strawberry. Some strawberry hemangiomas go away on their own by the time a kid is about 5 years old. Almost all strawberry hemangiomas go away by themselves by the time a kid is about 9 years old.
Another type of hemangioma is beneath the outer layer of skin. It's called a cavernous (say: ka-vur-nus) hemangioma. Cavernous means "like a cave," which is deep in the earth, like this type of birthmark is deep beneath the outer layer of skin. This kind of birthmark is puffier than a strawberry hemangioma. It's also a different color: not red like a strawberry, but more bluish-red.
Port-Wine Stains

Another kind of birthmark is a port-wine stain. This isn't puffy or raised like a strawberry or cavernous hemangioma — it's level with the outer layer of skin. A port-wine stain is an area of skin that is either maroon (a purplish-red color) or dark red. It gets its name from port wine, a type of wine that is dark maroon. Kids who have port-wine stains usually have them on the face and neck.
Doctors can sometimes use laser surgery to treat birthmarks so that they can't be seen as much. It's important to remember, though, that birthmarks really aren't a big deal and kids who have them aren't any different from kids who don't.
P.S. — If you have had any brown, blue, or black spots on your skin since birth, they are probably types of moles! Moles are tiny collections of pigment cells — cells that contain color. Like other birthmarks, moles don't hurt and usually aren't a sign of illness in kids. Sometimes they're even called beauty marks or beauty spots. But if you have questions about a mole or birthmark on your body, feel free to ask your doctor about it.