The evaluation of birthmarks involves a history and physical examination.

Physical findings in those with birthmarks include:

• Skin lesions:
• Bright red, purple or brown

Testing is not necessary to make the diagnosis of birthmarks. However, tests may be needed to identify the type of birthmark, or to investigate additional abnormalities that accompany birthmarks.

Tests that may be used to evaluate birthmarks include:

• Coagulation profile:
• For those who show signs of prolonged bleeding
• MRI:
• Useful for identifying the type of birthmark when the birthmark is large