I was scratching my chest, & i have a tiny mole that i almost scraped completely off. there was a little bit of blood. is this dangerous /serious?

Probably not: Scratching a mole off risks creating an infected wound and the scraped tissue is lost without pathology examination to determine the type and biological potential of the mole ( degree of atypia or risk of malignancy)

Unlikely dangerous: Cover it with aquaphor and a bandaid. If doesn't heal normally in a few weeks show a board certified dermatologist to be sure

See a dermatologist: A tiny mole that bleeds when scratched could be many things. You should see your dermatologist who can examine it with a trained eye and then recommend whether or not a biopsy is needed.

Probably not.: there are several conditions may fit your description of a "tiny mole": a true mole we called nevus. could be bloody after scratching, pose no harm if it stay small, no color/size change, round or oval shaped. Another condition called seborrheic keratosis, when early,would have a small "tough" pointed top. no harm if you scratch it off. Finally, a cyst/whitehead. no harm if you scratch off the top

See dermatologist: The bleeding is probably due to scratching, but it would probably still be best to see a dermatologist.