Most of us have some kind of birthmark somewhere (whether it's a tiny freckle or big "strawberry patch") and obviously most birthmarks are totally harmless. If anything, they give us character! But it's good to know the different kinds of skin discolorations because there are a few that aren't so harmless, and can signal a more serious underlying issue.

The most common potentially dangerous "birthmark" would be the mole, which looks like a raised freckle. Usually harmless, they just need to be watched closely for any changes in case they're developing into skin cancer. Other dangerous skin indicators are bluish puffy birthmarks (cavernous hemangiomas) because they can indicate vascular problems, and having several light tan marks called "cafe-au-lait spots" could signify neurofibromatosis -- a genetic tendency to develop skin tumors. And, according the article, that's it! The rest of the them are just there for looks.