A birthmark is a colored mark on the skin that is present at birth or appears shortly afterward. Birthmarks are very common and are usually harmless.
Why do birthmarks occur?
Birthmarks develop because of:
- An overgrowth of blood vessels (vascular birthmarks), or
- An excess of pigment-producing cells (pigmented birthmarks).
In most cases, the exact cause is unknown, and birthmarks are not caused by anything a parent did during pregnancy.
Common types of birthmarks
Vascular birthmarks
These are caused by blood vessels.
- Hemangiomas – raised red "strawberry" marks that often fade over time.
- Port-wine stains – flat red or purple patches that usually remain throughout life.
- Salmon patches – light pink marks often found on the eyelids, forehead, or back of the neck