When a toenail appears thickened and discolored, you may presume it is a fungal infection.  However, a nail injury from trauma or even micro trauma (repetitive minor trauma, such as a nail bumping up against a shoe) may damage a nail enough to appear as though it is infected, although it may not be.  The best way to determine if your nail is indeed infected with a fungus or not is with a nail biopsy.  This is a procedure that is done in the office. So if you have a question about that ugly nail, make an appointment with one of our doctors.