Nail disorders can be due to friction caused by shoes, fungus, a vitamin deficiency and may even be the cause of psoriasis. You may notice a change in the color, shape, thinning or thickening of the nails, pain, bleeding or discharge; even the skin around the nail can become inflamed and red. To determine the cause of the nail disorder a nail biopsy or culture may need to be performed for a definitive answer. There are treatment options available dependent of the source of the nail disorder.