text: dark marks under the finger nail? does anyone know what dark marks mean under the finger nail?  i have been getting them for a long time now, they start near the base of the nail and move up the nail as it grows.  it's not a bruise.  i know white marks are lack of calcuim but these are dark dark red lines.  any clues? the only thing i have had like that a when you have hit your fingers and a blood vessel under your nail bursts.  the dark bits in this case would be blood