Thickened, discolored nails happen often with age. One of the most common causes is a fungal infection called onychomycosis, which strikes about 50 percent of people over age 70.
Small cracks in the nail or the skin around it allow the fungus to enter the nail, and closed-toe shoes then provide a warm, moist environment for the fungus to thrive.
Treat the infection
You can try treating the infection with over-the-counter antifungal nail creams and ointments, but if you have a persistent infection or have diabetes, immune system disorders, or poor circulation, it’s important to see your primary care doctor, dermatologist, or podiatrist. Prescription treatments may include oral antifungal drugs such as terbinafine (Lamisil) and itraconazole (Sporanox), antifungal nail polish or creams, and/or removal of the damaged part of the nail in a process called debridement.
Use these steps to minimize the risk for fungal infections:
- Dry between your toes after a shower.
- Wear flip-flops in public showers.
- Use an antifungal powder.
- Allow your shoes to dry after wearing them.
- Clean inside shoes with vinegar and water or spray with a disinfectant.
- Wear socks that wick away moisture, such as those made from acrylic, wool, nylon, or polypropylene.
- Keep your nails trimmed to help prevent nail trauma, which makes it easier for fungus to get under the nail and flourish.