what causes purple toenail
Bleeding under the: nail. That is why your nail is purple. Your shoes caused pressure on your toenail and caused micro trauma to the nail and it bleeds. Not a bid deal. If there is a lot of blood, pressure and pain, it needs to be drained. So see a podiatrist. If not too bad, it will dry out and you nail will start to clear out.
A subungual hematoma is a condition in which there is bleeding under the fingernail or toenail. Usually caused by a crush injury, a subungual hematoma can cause symptoms such as intense pain and throbbing as blood collects under the nail.