Toenail fungus can be caused by various types of fungi such as yeasts or molds, which thrive in certain environments. When your nails, both toenails and fingernails, have small cracks or the skin surrounding them is neglected, it creates an opportunity for germs from fungal colonies to enter and cause an infection. In simpler terms, unsanitary conditions frequently result in fungal infections, underscoring the importance of proper nail care. You can keep your feet clean and scrub them regularly to ensure they remain dry yet moisturized, as well as clean the dirt from your nails to prevent fungal infections.