Fungal toenail infections are among the most frequent conditions treated in podiatry offices. Although they may begin subtly, they often progress into stubborn infections that are difficult to eliminate once fungus works its way beneath the nail plate. These infections can lead to thickened toenails, yellow or brown discoloration, brittle edges, and an odor that becomes hard to ignore. Since fungal nails take time to treat, prevention remains your strongest tool for keeping your nails clear and healthy.