Toenails are therefore particularly susceptible as fungi prefer dark damp places. Swimming pools, locker rooms and showers typically harbour these types of fungi. Chronic diseases such as diabetes, problems with the circulatory system, immune deficiency disease as well as a history of athlete's foot or excess perspiration also increase the chances of developing nail fungus.
The ageing process causes nails to become less moisturised and for cracks to appear. This is why children are less susceptible to nail fungus because their nails are usually stronger, healthier and without cracks. If your nails are cracked, naturally fragile or weakened as a result of an injury, it is easier for dermatophytes to infect a nail.