What is a common cause of nail fungus?

Moisture trapped under nail polish is a common cause of nail fungus because it creates an ideal environment for fungal growth. When moisture gets trapped, it can lead to dampness beneath the polish, which allows fungi to thrive. Nail polish can also seal in moisture and prevent air circulation, further contributing to conditions that favor fungal development. This makes it important for nail technicians to ensure that nails are clean and dry before applying polish to minimize the risk of fungal infections.

In contrast, while excessive filing can damage the nail and potentially allow for infection, it does not directly cause fungal growth as effectively as retained moisture. Using dirty tools certainly poses a risk for introducing infections, but fungi thrive in moist, warm environments, which is not necessarily the primary concern with tool hygiene. Allergic reactions typically involve skin irritation or inflammation rather than the specific conditions that facilitate fungal infections. Thus, moisture trapped under nail polish stands out as a significant and direct cause of nail fungus.