What Causes Toenail Fungus? The 7 Most Common Risk Factors

It's More Common Than You Think

Toenail fungus affects up to 14% of the general population, and men are twice as likely as women to get it. But what actually causes it?

1. Warm, Moist Environments

Fungi thrive in warm, damp conditions. Sweaty shoes, gym showers, pool decks, and locker rooms are prime breeding grounds. This is the #1 risk factor.

2. Age

Risk increases significantly after 40. Older nails grow slower, are thicker, and have reduced blood flow — all of which make them more susceptible to infection and slower to recover.

3. Nail Injury

Stubbed toes, ill-fitting shoes, sports injuries — any trauma to the nail creates gaps where fungi can enter. Even micro-trauma from running or hiking can create openings.

4. Athlete's Foot

As we've covered, athlete's foot and toenail fungus are caused by the same organisms. Untreated skin infections frequently spread to the nails.

5. Poor Circulation

Conditions like diabetes and peripheral vascular disease reduce blood flow to the feet, weakening the immune response in the nail bed. This makes it easier for fungi to establish and harder for your body to fight back.

6. Shared Surfaces and Tools

Walking barefoot in shared spaces (hotels, dorms, communal showers) and sharing nail clippers or files are direct transmission routes.

7. Genetics

Some people are simply more susceptible. If your parents had toenail fungus, you're more likely to get it — likely due to inherited immune and skin characteristics.

What You Can Do

You can't change your age or genetics, but you can control moisture, treat injuries promptly, and use a daily antifungal like CamoToe to both treat existing infections and prevent new ones.