How Common Is Toenail Fungus? Global Rates, Risk Factors, and Why Your Shoes Matter

How Common Is Toenail Fungus Around the World?

Toenail fungus is common everywhere, but the exact rate depends on how a study counts cases. A 2014 review in the Journal of the European Academy of Dermatology and Venereology found averages of about 4% in population studies and about 9% in hospital studies across Europe and North America.

The same review found that toenails are affected more often than fingernails, and that men are affected more often than women. Dermatophytes, such as Trichophyton rubrum, were the most common cause. The medical name for the condition is onychomycosis.

Many cases never get counted, because a discolored nail is often seen as a cosmetic issue instead of a health one. That makes a country by country map hard to build. Some reports suggest higher rates in North America and Europe than in some tropical countries, although the research is uneven, so read regional comparisons with care.

Why Do Toenail Fungus Numbers Disagree So Much?

The numbers disagree because studies count different people in different ways. Put side by side, the results can range from about 3% to more than 50%.

Three things explain most of the gaps:

• Who was counted. People who visit a clinic are more likely to have a nail problem, which is why hospital studies ran higher than population studies. The authors of the 2014 review noted that hospital studies may overestimate the true rate.
• How cases were confirmed. In the Turkish study, doctors thought about half of 321 people with type 2 diabetes had nail fungus from the look of the nails, but lab tests confirmed it in only 41 of them.
• Which fungi were counted. The 2015 review counted dermatophytes only. The 2014 review found that about one third of cases were caused by molds or yeasts instead.

So treat any single percentage as a range, and ask who was counted and how. People with diabetes also tend to be studied in clinics where foot problems are already a concern, which likely pushes those numbers higher.

Does Climate Affect Your Risk of Toenail Fungus?

Yes, warm and damp conditions help fungus grow, but climate is only part of the story. Dermatophytes feed on keratin, the protein found in your nails, skin, and hair. They generally grow best in moderate warmth, around 25 to 30°C (77 to 86°F), and they need moisture to take hold.

Here is how different climates shape your exposure:

• Tropical regions, such as Southeast Asia, equatorial Africa, and the Caribbean, stay warm and humid all year, so spores are always around.
• Subtropical regions, such as the southern United States and coastal China, have long warm and wet seasons that keep floors, soil, and shoes damp.
• Temperate regions, such as northern Europe and Canada, may see more cases in summer. Winter brings its own problem, because heavy boots and heated indoor spaces can recreate warm, damp conditions around your feet.

Researchers have found real differences between countries. A 2020 study in PLoS One tested 216 nail samples from Brazil, Canada, and Israel.

The usual fungus, T. rubrum, showed up in 98% of samples in all three places. But mixed cases, where a mold joined it, were more likely in Brazil, while a single dermatophyte was more likely in Canada and Israel.

A 2005 review in the Journal of the European Academy of Dermatology and Venereology also noted that the main cause of nail fungus varies with climate. This was a small sample from three countries, so it is a hint about geography and not a full map.

Why Do Your Shoes Matter More Than the Weather?

Your shoes create their own climate, and that climate often matters more than the weather outside. Closed footwear, such as leather work boots, synthetic sneakers, and winter boots, traps heat and sweat, so the air around your toes can be warmer and damper than the room you are standing in.

A 2013 review in the journal Mycoses linked the rise of toenail fungus during the twentieth century to closed footwear, along with wars and migration. This helps explain why someone in a cold, dry city can still face real risk. Open sandals give feet more airflow and help them dry faster, although barefoot walking on shared damp floors brings its own exposure.

Is Toenail Fungus Contagious?

Yes, toenail fungus can spread from person to person, mostly through shared warm, wet surfaces. In gym showers, locker rooms, and pool decks, a person with a fungal nail problem sheds tiny flakes of skin and nail that carry spores. The next barefoot walker can pick them up, especially if the skin has small cracks.

Pools show the pattern clearly. A 2016 study in Mycopathologia checked 169 employees at 21 swimming pools in Israel. About 46% had both athlete's foot and toenail fungus, compared with about 10% of the comparison group. After adjusting for age and gender, the pool employees were about 20 times more likely to have both.

That study also shows how closely the two problems travel together. Athlete's foot is a fungal skin problem, and it often shows up alongside nail fungus, so it is worth checking the skin between your toes too.

Shared living spaces add to the spread. The Mycoses review found toenail fungus to be very common in families, boarding schools, military quarters, and nursing homes. If someone at home has it, avoid sharing towels, nail clippers, and shoes.

Cosmetic foot care can add risk when tools are not cleaned properly. Clippers, files, and foot baths that are not sanitized between clients can carry fungus from person to person. If you enjoy pedicures, our guide on going to the nail salon with toenail fungus covers what to ask before you book.

Which Jobs and Activities Raise the Risk?

Jobs and sports that keep your feet hot, sweaty, and enclosed for hours raise the risk the most. Common examples include:

• Military personnel, who wear heavy boots for long stretches, often in warm climates and shared quarters.
• Athletes, such as distance runners, soccer players, and hockey players, who spend hours in sweaty shoes. Small, repeated injuries to the toenail from kicking or stopping suddenly can also give fungus an easy way in.
• Industrial and construction workers in steel toe boots, especially on long shifts in humid weather.
• Farmers, fishers, and professional cleaners, whose shoes and feet stay wet for much of the day.
• Pool and locker room staff, who spend long shifts on warm, wet floors.

Who Is Most at Risk of Toenail Fungus?

Older adults and people with diabetes face the highest risk. A 2015 systematic review in the Journal of the European Academy of Dermatology and Venereology found clearly higher rates in both groups than in the general population. The authors linked this to weaker immune response, reduced blood flow to the feet, and changes in the nail itself.

Children are rarely affected, which is why this is mostly an adult story. Family history also seems to matter. Studies of people with diabetes in Turkey and Thailand both linked family history to higher rates, and the 2013 Mycoses review lists genetics among the risk factors. That may help explain why one person in a household gets nail fungus while another never does.

If you have diabetes, check your feet and nails regularly and mention any nail change to your doctor, since foot problems can be harder to notice and slower to heal.

Quick Self Check: Which Risk Factors Apply to You?

There is no official score, but a simple check shows where to focus. Start with the factors you cannot change:

• Being older.
• Being male.
• Having a family history of nail or foot fungus.
• Having diabetes or reduced circulation in the feet.

Now the factors you can change:

• Wearing tight, closed shoes for most of the day.
• Wearing the same pair daily without letting it dry.
• Walking barefoot in gym showers, locker rooms, or pool areas.
• Getting pedicures at places that do not clean their tools.
• Leaving athlete's foot on the skin unaddressed.

If you match items in the first list, that is a reason to check your feet more often, not a reason to worry. The second list is where small habit changes can lower your exposure.

What Does Toenail Fungus Look Like, and What Else Could It Be?

Toenail fungus often shows up as a nail that turns yellow or white, thickens, crumbles at the edge, or lifts away from the nail bed. Doctors call the buildup under the nail subungual hyperkeratosis and the lifting onycholysis. In plain terms, that means thick material under the nail and a nail that no longer sits flat.

A nail that looks fungal is not always fungal. A 2014 review in La Presse Medicale noted that fungus accounts for about half of all nail problems, which means the other half have different causes. A 2020 study in the Journal of Cosmetic Dermatology tested 53 people with nail changes and found no fungus in 17 of them, or about 32%. It was a small clinic study, so treat it as an example and not a rule.

Injuries, other skin conditions, and some health conditions can change the nail in similar ways. Our guide on telling nail trauma from a fungal problem covers the differences in more detail.

What a Nail Test Involves

A nail test is usually quick. The doctor takes a small clipping or scraping from the nail, looks at it under a microscope with a special solution, and often grows a sample in a lab dish to see what is there.

No test is perfect. A 2005 review noted that lab cultures can miss about 30% of cases, so a doctor may repeat the test when the signs strongly point to fungus.

How Can You Lower Your Risk and Keep It from Coming Back?

The best defense in any country is to break up the warm, damp climate around your feet. These everyday habits help:

• Dry your feet completely after bathing, especially between the toes.
• Rotate your shoes so each pair has about 24 hours to dry between wears.
• Choose moisture wicking socks, such as merino wool or synthetic blends, instead of 100% cotton, which holds dampness against the skin.
• Wear sandals or shower shoes in public gyms, pools, and hotel bathrooms.
• Ask salons how they clean their tools before a pedicure.

Explore more daily habits to prevent toenail fungus.

Why Shoes and Socks Can Cause a Repeat Round

Toenail fungus has a reputation for coming back. A 2016 review in Seminars in Cutaneous Medicine and Surgery described it as a long lasting condition with a high recurrence rate. A 2025 review in the journal Biology added that shoes, socks, and foot care tools are an under recognized source of reinfection.

Researchers in Denmark put fungus on small pieces of sock in a 2022 study in Mycoses, then tested common ways to clean them.

This was a lab test on sock pieces, not on people, so it does not tell you exactly how to wash your own socks. It does suggest that a normal wash may not be enough on its own. Give your shoes, socks, and nail tools the same attention you give your feet, and ask your doctor or podiatrist what makes sense for your situation.

When Should You See a Doctor About a Toenail Change?

See a doctor or podiatrist if a nail turns yellow, thickens, crumbles, or becomes painful, or if you have diabetes or poor circulation and notice any nail change. A professional can tell fungus from other causes and explain your options.

If you feel self conscious about your feet, you are not alone. A 2020 study in Skin Appendage Disorders asked 100 people with toenail fungus about daily life and found a moderate effect on quality of life. Social embarrassment and the hassle of seeking care were among the most bothersome parts.

Early attention matters. In many cases, toenail fungus does not go away by itself, and it can spread to nearby nails, the skin around them, or other people who share bathroom floors. To learn why it can be so stubborn, read our article on the risks and complications of toenail fungus.

Key Takeaways

• Toenail fungus is common worldwide, but rates range from about 3% to more than 50% depending on who was studied and how cases were confirmed.
• Warm, damp conditions help fungus grow, but the climate inside your shoes often matters more than the weather outside.
• Toenail fungus can spread through shared wet spaces such as gym showers, pools, salons, and family bathrooms.
• Older age, diabetes, family history, and jobs or sports with sweaty, enclosed footwear raise risk. Children are rarely affected.
• Many nail changes are not fungus, so a nail sample test is the reliable way to know what is behind them.
• Shoes, socks, and nail tools can keep the fungus around, so caring for them matters as much as caring for your feet.
• Dry feet, rotated shoes, moisture wicking socks, and shower shoes in public spaces help lower your risk.