What causes purple toe nails and how do i treat it?

See below: This could be from decreased circulation or from thin toenails that allow the color of the nailbed to show thru. Best to see a doctor.

Have it looked at.: Most probable reason for this is trauma or use of tight shoes. This can cause bleeding under the nails. Try wearing shoes with a wider and higher toe box. Have the feet inspected by a professional to determine the exact cause of the problem, as treatment varies depending on the diagnosis.