Fungi that are already present in or on your body can cause nail infections. If you have come in contact with someone else who has a fungal infection, it may have spread to you. According to the American Academy of Dermatology (AAD), fungal infections affect toenails more commonly than fingernails because your toes are usually confined to your shoes, where they’re in a warm, moist environment.
If the fungal infection has spread to the toenails, the nails must also be treated to avoid reinfection of the feet. Often, the nails are initially ignored only to find the athlete's foot keeps recurring. It is important to treat all of the visible fungus at the same time. Effective nail fungus treatment may be more intensive and require prolonged courses (three to four months) of oral antifungal medications.
Ozonized oils such as olive oil and sunflower oil are “injected” with ozone gas. According to a 2011 study, this type of ozone exposure in low concentrations for a short duration can then inactivate many organisms such as fungi, yeast, and bacteria. Another study found ozonized sunflower oil was more effective in treating toenail fungus than the prescription topical antifungal, ketoconazole (Xolegel).
Ciclopirox (Penlac) topical solution 8% is a medical nail lacquer that has been approved to treat finger or toenail fungus that does not involve the white portion of the nail (lunula) in people with normal immune systems. In one study, ciclopirox got rid of the fungus 22% of the time. The medication is applied to affected nails once daily for up to one year. The lacquer must be wiped clean with alcohol once a week.
Green nails can be caused by Pseudomonas bacteria, which grow under a nail that has partially separated from the nail bed. This infection may cause a foul odor of the nails. The treatment is to trim the nail short every four weeks, don't clean it, polish if you want to hide the color, and wait two to three months. It is also advised to avoid soaking the nail in any sort of water (even if inside gloves) and to thoroughly dry the nail after bathing. If the problem continues, there are prescription treatments that your doctor may try.
Use soap and water to wash your feet, and dry well, including between toes. Trim your toenails -- straight across -- to keep them shorter than the end of your toe. Make sure the tools you use are clean, too. Wash clippers and files with soap and water, then wipe with rubbing alcohol. You might be tempted to cover up discolored nails with polish, but don't. Your nail bed can't "breathe," which keeps fungus from going away.