Is the black spot on my toe a bruise or toenail fungus? how to tell?

See the podiatrist: A bruise is the result of a blood blister under the nail plate which can lift the nail plate from the underlying bed. This could lead to toenail fungus. However, not all black spots are bruises or infections, like fungus. There is other growths that discolor the nails, including some cancers. To be safe, have a podiatrist examine your toenail.

Third possibility?: In this case, the best thing to do is to take a biopsy. The thing i would be concerned most with, and this is a very small chance, is some sort of skin cancer (melanoma). This is very important that you check this one out.