Toenail Fungus: Symptoms, Causes, Treatment and Prevention
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer: What is toenail fungus?
Toenail fungus, or onychomycosis, is a common fungal infection in or under a toenail, usually caused by dermatophytes entering through a crack or cut. It can make the nail discolored, thickened, misshapen or separated from the nail bed. It is usually painless but can be hard to treat, spread and return. Treatment options include oral or topical antifungals.
What the research says
Oral antifungals clear the infection far more often than placebo, and terbinafine probably edges out azoles. A Cochrane review of 48 trials (10,200 participants) found high-quality evidence that terbinafine was more effective than placebo for clinical cure (risk ratio 6.00, 95% CI 3.96 to 9.08; 8 studies, 1,006 participants) and mycological cure (RR 4.53, 95% CI 2.47 to 8.33). Azoles were also more effective than placebo for clinical cure (RR 22.18, 95% CI 12.63 to 38.95; 9 studies, 3,440 participants). Terbinafine was probably more effective than azoles for clinical cure (RR 0.82, 95% CI 0.72 to 0.95; 15 studies, 2,168 participants) with probably no difference in adverse events, and evidence on recurrence was low quality (Kreijkamp-Kaspers et al., Cochrane Database Syst Rev, 2017). [1]
Continuous oral treatment beat topical treatment for clearing the fungus. A network meta-analysis of 26 randomized trials (8,136 patients), selected from 77 identified, found that the odds of mycological cure with continuous terbinafine 250 mg or continuous itraconazole 200 mg were significantly greater than with topical treatments. Fluconazole, pulse regimens of terbinafine and itraconazole, and topical treatments did not differ significantly from one another, and the odds of adverse events were not significantly different between oral and topical treatments (Gupta et al., Br J Dermatol, 2020). [2]
Confirm the diagnosis and individualize the plan. A review of antifungal drug use advises a definitive mycological diagnosis and an individual assessment of risks and benefits before starting treatment. It describes oral terbinafine as the treatment of choice, followed by pulsed itraconazole, and notes that oral therapy offers a greater likelihood of cure than topical therapy but carries greater risks and needs closer monitoring (Thomas et al., Am J Ther, 2019). [3]
What does toenail fungus look like?
Toenail fungus can change the nail's color, shape and texture. Affected nails may look white, yellow or brown. Some areas may appear chalky or cloudy.
The nail may become thicker and misshapen. It may separate from the nail bed, leaving space between the nail and the tissue underneath. Cracks or breaks may develop in one or more places.
These changes are not enough to confirm the cause by appearance alone. Other nail problems can look similar, so a provider may recommend testing before treatment.
Is toenail fungus painful?
Usually, no. Toenail fungus often affects how the nail looks rather than causing pain. Some people may feel self-conscious about the appearance of a discolored or thickened nail.
Pain, redness or pus near the toenail is different. These changes can signal a complication or another problem and should be discussed with a healthcare provider, especially when diabetes, circulation problems or a weakened immune system is present.
What causes toenail fungus?
A type of mold called a dermatophyte causes most cases of tinea unguium. Dermatophytes are microscopic fungi that use keratin, the protein that gives fingernails and toenails their hardness.
Other types of fungi can also infect toenails. Fungi can get between the nail and nail bed through a crack or cut in the toe.
Cause or exposure | Why it matters |
Crack or cut | A break in the skin or nail area can give fungi an entry point. |
Warm, moist spaces | Nail fungi grow well in warm, moist, dark environments. |
Communal wet areas | Public pools, locker rooms and showers can expose bare feet to infected surfaces. |
Direct contact | Some nail fungi can spread through contact with an infected person. |
Nail trauma | Injury or aggressive clipping can create a portal of entry. |
Is toenail fungus contagious?
Many types of toenail fungus, including tinea unguium, can spread through direct contact or by touching an infected surface. Warm, moist, dark environments can make exposure more likely. [5]
Public locker rooms, showers, swimming areas and other communal places where people walk barefoot are common settings for exposure. Wearing flip-flops in these areas can help reduce contact with contaminated surfaces. [5]
A household member with foot or nail fungus can also increase exposure. When possible, avoid direct contact with the infection and consider using a different shower or wearing flip-flops in the shower.
Can toenail fungus spread to other parts of the body?
Toenail fungus usually remains around the toe, but some dermatophytes can spread to other nails and areas containing keratin. [5]
Possible areas include other toenails, the skin between the toes, the groin and the scalp. When dermatophytes infect the skin, the condition may be called ringworm. Infection between the toes is known as athlete's foot, and infection in the groin is called jock itch.
Putting socks on before other clothing may reduce the chance of spreading fungus from the feet to other areas.
Who is more likely to get toenail fungus?
Anyone can develop toenail fungus. It often affects older adults, particularly people over 60. The condition is also common overall, and the likelihood increases with age.
Risk may be higher if you have:
Athlete's foot.
Diabetes.
Hyperhidrosis, or unusually heavy sweating.
A nail injury.
Poor blood circulation caused by peripheral vascular disease.
Psoriasis.
A weakened immune system, including from an autoimmune disorder or HIV.
A risk factor does not prove that a nail change is fungal. It simply makes professional assessment more useful when a nail looks abnormal.
How common is toenail fungus?
Toenail fungus is very common, although estimates vary by study and population. One commonly cited estimate places onychomycosis at about 1 in 10 people overall and as many as 1 in 2 people older than 70. A systematic review reported that fungal infections affect 3% to 5% of people in the general population but account for about 50% of nail conditions seen by dermatologists (Ferrari, BMJ Clin Evid, 2011).
Because many nail problems can resemble one another, prevalence does not mean every thick or discolored nail is fungal. Testing may help clarify the cause.
How is toenail fungus diagnosed?
A healthcare provider usually starts by examining the affected nail closely and reviewing symptoms and relevant health history. The appearance may suggest toenail fungus, but visual inspection alone may not be enough to confirm it.
The provider may take a small sample from underneath the nail. The sample can be examined under a microscope to look for fungal cells. If an initial test is negative, a scraping may be sent for culture to see whether fungus grows and to help identify the type.
Confirming the cause can be helpful because treatment may last several months and some medications require monitoring.
How is toenail fungus treated?
Toenail fungus can be difficult to treat. Treatment may continue for several months or longer, and the infection can come back. A dermatologist or podiatrist can explain available options.
For a mild case that does not bother you, a healthcare provider may recommend no treatment. When treatment is appropriate, the choice depends on the symptoms and the person's overall situation.
Treatment approach | What to know |
Oral antifungal medication | Prescribed medicines may be taken daily for several months or longer. They can affect the liver and interact with other medicines, so they are not suitable for everyone. Blood tests may be used to monitor possible side effects. |
Topical medication | Applied directly to the nail and used regularly over time. It may be paired with oral treatment. |
Laser treatment | May temporarily increase the amount of clear nail, but it is not a cure and is not typically a first-line approach. |
No treatment | May be reasonable for a mild case that is not bothersome, if recommended by a provider. |
Oral antifungal medication
Prescribed oral options include terbinafine, itraconazole and fluconazole. They may be taken every day for several months or longer.
These medicines can affect the liver and interact with other medications. A provider may use blood tests to check for potential side effects. Oral antifungals are not appropriate for everyone and should not be started without professional guidance.
Topical medication
Topical antifungal medication is applied directly to the nail and treats the fungus gradually. It needs regular use over time. Topical treatment may be most effective when paired with oral medication, but a provider should determine whether combination treatment is appropriate.
Laser treatment
Laser treatment directs a laser beam and special lights at the toenail. It may temporarily increase clear nail, but it is not a cure. Cure rates are lower than those associated with oral and topical medications, and laser treatment is not typically used first.
What is the most effective treatment for toenail fungus?
The most appropriate treatment depends on the symptoms and the person's situation. A healthcare provider considers these factors before recommending a plan.
Overall, oral antifungal medication may offer the most treatment potential. Combining an oral medicine with a topical antifungal may make treatment more effective, but the risks, interactions and monitoring needs mean that the plan must be customized by a qualified provider.
No treatment works instantly. The nail must grow out, and treatment may last for several months or longer. Even after treatment, the infection can return.
Can toenail fungus go away on its own?
Toenail fungus can be difficult to treat, and a provider may recommend no treatment for a mild case that does not bother the person. Whether to treat depends on the symptoms, health situation and personal priorities.
If you have diabetes, circulation problems or a weakened immune system, do not rely on self-assessment alone. Ask a healthcare provider how the nail should be evaluated and managed.
Can I wear nail polish if I have toenail fungus?
Nail polish may trap moisture under the nail bed. Because fungi thrive in moist environments, polish may make a fungal infection worse, especially when a topical antifungal is being used.
A healthcare provider may recommend avoiding nail polish. The nail continues to grow with or without polish.
How can I prevent toenail fungus?
No prevention step guarantees that toenail fungus will not occur. However, practical foot-care habits can reduce exposure and lower the chance of recurrence.
Prevention step | Practical example |
Protect feet in communal areas | Wear flip-flops in public showers, locker rooms and swimming areas instead of walking barefoot. |
Reduce household exposure | If a family member has foot or nail fungus, avoid direct contact and consider a different shower or shower flip-flops. |
Clean nail tools | Disinfect or clean nail trimmers before using them. |
Avoid nail trauma | Do not tear, rip or aggressively clip the toenails. |
Keep feet dry | Dry your feet fully after bathing. |
Trim carefully | Soak nails or cut them after a shower, then trim straight across rather than rounding the edges. |
Choose suitable shoes | Wear shoes that fit correctly and are not too loose or tight around the toes. |
Follow diabetes foot-care advice | If you have diabetes, follow the foot-care recommendations provided by your healthcare professional. |
How do I care for my feet while living with toenail fungus?
Keep the feet clean and dry, and continue careful nail trimming. Avoid tearing or ripping the nail. Straight-across trimming can reduce accidental injury to the surrounding skin.
Wear shoes that fit well around the toes. In communal wet areas, use flip-flops. If you have diabetes, regular foot exams may help identify foot problems before they become serious.
If the nail is being treated with a topical medication, ask the prescriber whether nail polish or other products should be avoided.
When should I see a healthcare provider?
Seek treatment guidance if you have a discolored or thickened toenail and are unsure of the cause. Professional advice is especially important when you have diabetes, circulation problems or a weakened immune system.
Contact a healthcare provider promptly if you notice:
Redness near the toenail.
Pain near the toenail.
Pus near the toenail.
A rapidly worsening foot problem.
Signs of infection in a person with diabetes or poor circulation.
In rare cases, toenail fungus can contribute to cellulitis. Without prompt treatment, cellulitis can pose a serious danger to health.
What questions should you ask at a toenail fungus visit?
Useful questions at a toenail fungus visit include what type of infection you have, how long treatment takes, possible medicine interactions and how to prevent recurrence.
What type of nail infection or nail change do I have?
Do you recommend treatment, and why?
Should a sample be examined under a microscope or sent for culture?
How long might treatment take?
Could any of my current medicines interact with an oral antifungal?
Would blood tests be needed during treatment?
What steps can I take to reduce recurrence?
Should I avoid nail polish while using a topical medication?
Which complications should prompt urgent follow-up?
Conclusion
Toenail fungus, also called onychomycosis or tinea unguium, can make a nail white, yellow or brown, chalky, thick, misshapen, separated or cracked. It is usually not painful, but it can be persistent, contagious and difficult to treat.
A healthcare provider may confirm the cause with a nail sample before recommending treatment. Depending on the situation, care may include monitoring, prescribed oral or topical antifungals or selected procedures. Treatment often takes several months, and recurrence is possible.
Protect your feet in communal wet areas, keep them dry, clean nail tools, trim straight across and wear shoes that fit correctly. If you have diabetes, circulation problems or a weakened immune system, or if the area is red, painful or producing pus, seek professional guidance promptly.
If a toenail has become thick, discolored, cracked or separated from the nail bed, schedule an evaluation with a qualified healthcare provider to confirm the cause and discuss the safest next step.
Frequently Asked Questions
What are the first signs of toenail fungus?
Early or noticeable changes can include white, yellow or brown discoloration, chalky or cloudy spots, thickening, misshaping, separation from the nail bed, and cracks or breaks.
Is toenail fungus the same as onychomycosis?
Onychomycosis is another name for toenail fungus. When a dermatophyte causes the infection, it may also be called tinea unguium.
Is toenail fungus contagious?
Many types can spread through direct contact or infected surfaces. Public showers, locker rooms, swimming areas and other places where people walk barefoot can expose feet to fungi.
Can toenail fungus spread to other nails?
Yes. It may spread to other toenails and, less commonly, fingernails. It can also affect skin between the toes, the groin or the scalp.
Does toenail fungus hurt?
Usually not. Toenail fungus generally is not painful, although pain, redness or pus near the nail should be evaluated by a healthcare provider.
How long does toenail fungus treatment take?
Treatment may continue for several months or longer. The infection can return even after treatment, so follow-up and prevention matter.
What is the strongest treatment for toenail fungus?
The best option depends on the person's symptoms and health situation. Oral antifungals may offer the most treatment potential, and combining oral and topical treatment may improve effectiveness, but a provider must decide what is appropriate.
Can I treat toenail fungus with over-the-counter products?
A topical medication may be used directly on the nail, but the cause of a nail change should be confirmed and treatment should be discussed with a healthcare provider, particularly if you have diabetes, circulation problems or a weakened immune system.
Can laser treatment cure toenail fungus?
Laser treatment is not a cure. It may temporarily increase clear nail and is not typically a first-line treatment.
Should I use nail polish over toenail fungus?
Nail polish can trap moisture and may make fungal infection worse, especially when a topical antifungal is being used. Ask your provider whether to avoid polish.
How can I prevent toenail fungus from coming back?
Keep feet dry, wear flip-flops in communal wet areas, clean nail trimmers, avoid aggressive clipping, trim straight across and wear shoes that fit correctly. Follow professional foot-care recommendations if you have diabetes.
When is toenail fungus urgent?
Seek prompt care for redness, pain or pus near the toenail, especially if you have diabetes, circulation problems or a weakened immune system. Rarely, infection can lead to cellulitis.
References
Kreijkamp-Kaspers S, Hawke K, Guo L, et al. Oral antifungal medication for toenail onychomycosis. Cochrane Database Syst Rev. 2017;7(7):CD010031. PMID 28707751. https://doi.org/10.1002/14651858.CD010031.pub2
Gupta AK, Foley KA, Mays RR, et al. Monotherapy for toenail onychomycosis: a systematic review and network meta-analysis. Br J Dermatol. 2020;182(2):287-299. PMID 31120134. https://doi.org/10.1111/bjd.18155
Thomas J, Peterson GM, Christenson JK, et al. Antifungal drug use for onychomycosis. Am J Ther. 2019;26(3):e388-e396. PMID 31082864. https://doi.org/10.1097/MJT.0000000000000696
Ferrari J. Fungal toenail infections. BMJ Clin Evid. 2011;2011:1715. PMID 21846413. https://pubmed.ncbi.nlm.nih.gov/21846413/
Ludmann P. Nail Fungus: FAQs. American Academy of Dermatology Association. Last updated June 26, 2025. https://www.aad.org/public/diseases/a-z/nail-fungus-overview
National Library of Medicine. Fungal Infections. MedlinePlus. Last updated September 21, 2025. https://medlineplus.gov/fungalinfections.html
Disclaimer
This article is for general educational purposes and is not a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition.
It is educational content, not a diagnosis, prognosis or personalized treatment plan. A qualified healthcare professional should interpret nail changes, decide whether testing is needed, review medication interactions and liver-monitoring needs, select treatment, and advise people with diabetes, circulation problems or weakened immunity. If redness, pain or pus appears near the toenail, seek prompt professional care.
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