Those yellowish and thickened toenails could mean you have an infection with a toenail fungus. Here are the types, symptoms, and how to treat fungal infections of the toenail.
4 Types of Toenail Fungus and How To Treat Them
Updated on Mar. 24, 2025
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If your toenail becomes discolored with white or yellow spots, it could signify the beginning of toenail fungus, or onychomycosis, as doctors call it. These pesky fungi are to blame for about 50% of nail problems. “In my experience, that statistic is quite accurate,” says Hannah Kopelman, MD, a dermatologist at Kopelman Aesthetic Surgery in New York and host of the Derm Club podcast. “About half of the nail issues I encounter are related to toenail fungus.”
Toenails are also affected seven to ten times more often than fingernails because of their slower growth, lower blood supply, and restriction in shoes.
Still, a toenail fungus doesn’t pose a danger to your overall health—unless it goes untreated. If the fungus has free rein, it can cause even more discoloration and the nail to become thick and brittle. The nail may even fall off, and it could spread to the other nails in your foot.
“Fungal infections of the foot and toenails rarely, if ever, resolve on their own. They almost always require prescription management for resolution,” says Joseph Zahn, MD, a dermatologist at George Washington University Medical Faculty Associates.
Here’s what you should know about the types, symptoms, and risks of toenail fungal infections and how to treat them.
What is toenail fungus?
Toenail fungus is a fungal infection that affects the toenail plate, though it can infect the nail bed and surrounding skin tissue, too. “[It’s] commonly caused by fungi called dermatophytes, although yeasts and molds can also cause it,” says Dr. Kopelman.
Medically, the broad term for toenail fungus is onychomycosis—but if it’s caused by the dermatophytes fungi specifically, doctors refer to that as tinea unguium.
“Fungus is found everywhere and looks for opportunities to get into the skin and nails,” explains Timothy Curran, DPM, MD, FACFAS, a podiatrist at Tufts Medical Center. “Fungi like warm, dark, moist environments, and peoples’ feet are among the best places to get into the skin and nails.”
Dr. Curran says that people with toenail fungus may have scaling, reddish, peeling skin on the bottom of the feet; yellowish, crumbling nails; redness around the nails; and occasional pain in the toes and feet.
Types of toenail fungus
“The symptoms of most fungal toenail infections are similar,” says Dr. Zahn. The hallmark symptoms include:
- nail discoloration
- nail separation
- brittleness
- thickening of the nail
- sometimes pain
Yet, those symptoms are present in other conditions like psoriasis or from banging your toenail. With the symptoms so similar, it’s difficult to identify the type of fungal infection on your own. Your doctor or dermatologist may take a small sample of the debris beneath the nail, trim the nail, or scrape a tiny bit of skin to pinpoint the type of fungus.
1. Distal Subungual Onychomycosis
Dr. Kopelman says this type of toenail fungus is the most common one she sees in patients. With distal subungual onychomycosis, the fungus invades the nail bed underneath the nail. “It usually begins at the edge of the nail and gradually moves inward, causing notable changes in appearance and texture.”
Still, while its prevalence may not be encouraging if you have it, it is good news when it comes to treating it.
“Since distal sublingual onychomycosis is the most common subtype, we have the most information about how to treat the infection effectively,” says Shari Lipner, MD, PhD, a dermatologist and the Director of the Nail Divison at Weill Cornell Medical Center.
Signs and symptoms
- More common in the big toenail than other toenails
- Thickening of nails, usually yellowish-white to yellowish-brown in color, or may appear as yellow streaks in the center of the toenail
- The nail may be jagged and chipped or come apart from the nail bed
- Pain and mild inflammation in the toenail area
2. White Superficial Onychomycosis
White superficial onychomycosis is less common than distal subungual onychomycosis and presents differently.
“The infection is on the top layers of the hard part of the nail, not deep under the nail, so it’s generally easier to treat,” says Dr. Lipner. Unlike other fungal infections, which can affect fingernails and toenails, white superficial onychomycosis affects only the toenails.
Signs and symptoms
- Small, white, speckled “islands” randomly appear on the surface of the nail plate
- Nail becomes rough, soft, and crumbles easily
3. Candida Onychomycosis
“Candida is a yeast that is found in the environment and sometimes just lives on the skin as a part of our normal skin flora,” says Dr. Zahn. It actually attacks the soft tissue around the toenail first, then penetrates the toenail.
Toenail fungus caused by yeast is less common than infections from other types of fungi, says 2023 research published in Frontiers in Medicine. However, candida onychomycosis is more prevalent in older adults, particularly those with diabetes, psoriasis, or immunodeficiencies. If there’s existing nail trauma (meaning there’s an easy way for the yeast to get in), chronic exposure to moisture and chemicals like detergents and soaps can contribute to Candida onychomycosis as well, per 2021 research published in the Indian Journal of Dermatology.
It’s difficult to tell the difference between Candida toenail fungus and another fungus without taking a sample and having it tested. It also typically affects the fingernails more often than the toes, especially if hands are routinely in water.
Signs and symptoms
- The skin around the toenail is reddish
- Nail has white, brown, or yellow discoloration
- Nails may become brittle and split, causing partial or total destruction of the nail
4. Proximal subungual onychomycosis
This rare toenail infection begins when the fungus invades from the proximal skin—where the nail meets the toe, behind the toe’s cuticle, and progresses distally across the nail. As it spreads, it penetrates the newly forming nail.
“Proximal toenail infections, especially those that progress quickly, have been associated with immunosuppression, including HIV/AIDS, but it can be seen in otherwise healthy people, albeit uncommonly,” says Dr. Zahn.
Signs and symptoms
- Starts as a diffuse white patch in the center of the cuticle
- As the toenail grows out, white spots move outward
- The toenail separates from the nail bed, destroying the toenail
Risk factors for toenail fungal infections
A fungus can invade the toenails of anyone at any age, but it is far more common in older adults. “Studies show that 75% of people 75 and older have some fungal infections of the skin and nails,” Dr. Curran says. The odds are higher because blood flow is reduced as we get older, which slows nail growth. Nails become more dry and brittle, causing them to crack.
A fungus can enter through a break in the skin or under or beside the toenail. And quite frankly, toenails just get more difficult to reach and trim as our flexibility declines.
“Longer nails are more prone to trauma, so older adults who may have trouble trimming their nails are at risk for trauma and subsequent infection,” says Dr. Lipner.
Still, our experts say that other risk factors for toenail fungal infections include:
- Exposure to warm, moist environment: “Places like public showers, locker rooms, or damp shoes are common culprits,” says Dr. Kopelman.
- A weakened immune system
- Diabetes
- Psoriasis
- Poor circulation
- Use of shared instruments, like toenail clippers or nail files
- Athlete’s foot (a fungal infection of the skin between the toes)
In addition, “Trauma causing a break in the skin around the nails can allow the fungus easier access to the nails,” says Dr. Curran.
How to treat toenail fungal infections
A toenail fungus might not seem like a big deal compared to other health conditions, but it can affect daily life activities and function to some degree. “Some patients experience pain, difficulty doing everyday activities, and fitting shoes,” says Dr. Lipner. “There is also a stigma surrounding nail fungus, and so many people are embarrassed that they have this,”
Still, treatment is essential, says Dr. Kopelman. “If left untreated, toenail fungus often progresses, causing nails to become thicker, brittle, or distorted,” she says. This can cause pain and discomfort on its own, but “There’s also a risk the infection will spread to adjacent nails or skin, and secondary bacterial infections can develop, particularly in individuals with weakened immune systems or underlying conditions like diabetes.”
Home remedies for toenail fungal infections
As a rule, toenail fungal infections require medical treatment. Over-the-counter products and at-home care might help some of the symptoms, but it’s a temporary fix. To completely eradicate the fungus and keep it from spreading to other nails—or people—prescription medicine is necessary.
However, our experts say that there are some home remedies that can ease symptoms and potentially help prevent the toenail fungus from getting worse.
Dr. Kopelman advises her patients to keep their nails clean, short, and dry to manage symptoms at home. “Using antifungal sprays or powders in shoes and socks can help control fungal growth,” she says. “Additionally, it’s important to avoid walking barefoot in shared spaces and choose breathable shoes to reduce moisture, which fungi love.”
If you suspect you have a toenail fungal infection, Dr. Curran also suggests using bleach products to clean your tub and shower areas, changing socks as soon as they become soiled or wet, and wearing breathable or open-toe shoes when possible.
“Many of the over-the-counter medications are weak and don’t kill the fungus,” he warns. “Topical treatments like apple cider vinegar, tea tree oil, and Vicks VapoRub have shown to provide little effect on toenail fungus.”
Prescriptions for toenail fungal infections
Fair warning—getting rid of toenail fungus isn’t a “one and done” kind of treatment. “It’s a one-year cure with both orals and topicals,” says Dr. Lipner. “Orals are taken for three months, and topicals are taken for one year.”
However, topical medications alone may be effective if the infection is milder or the fungus just involves part of the nail, Dr. Curran says.
The prescription antifungal medications our experts most often turn to include:
- Terbinafine (Lamisil) or itraconazole (Sporanox): These oral medications are the gold standard, especially for severe infections when the entire nail is infected, Dr. Curran says.
- Ciclopirox: A topical treatment that Dr. Kopelman may recommend in milder cases.
- Jublia (efinaconazole): A newer topical antifungal that can be effective in eradicating toenail fungus, says Dr. Curran. It penetrates the nail plate to reach the nail bed, inhibiting existing fungi from growing and reproducing right at the source, explains Dr. Lipner.
“The exact medication does depend on the specific type of fungus, the severity of the infection, and the patient’s overall health,” Dr. Kopelman explains.
Treating a toenail fungal infection can take so long because toenails grow slowly—about one millimeter per month—so it takes at least a year for an entirely new, healthy toenail to grow. Treatment plans vary depending on the medication, fungus type, and severity, but typically:
- Topical antifungal medications are applied to the toenail daily or weekly.
- Antifungal oral medications are taken in addition to the topical treatment, as advised by your doctor.
It’s rare, but when medication doesn’t resolve the problem, the toenail can be removed surgically or non-surgically with a chemical applied to the nail. The nail can grow back, but if the fungus is persistent, a dermatologist can treat the nail so it doesn’t grow back.
Potential side effects and complications from treating toenail fungal infections
Dr. Kopelman and Dr. Curran say that oral antifungal medications can sometimes cause:
- Gastrointestinal discomfort (including abdominal pain, nausea, gas/bloating, and other symptoms)
- Headaches
- Increased sun sensitivity
- Adverse interactions with other medications, including some anti-depressants and beta-blockers, according to 2024 research published in Infection and Drug Resistance
It’s rare, but they can also cause liver issues, “So I may monitor liver function during treatment,” Dr. Kopelman explains.
“Topical treatments are typically very safe but can occasionally lead to skin irritation or allergic reactions,” she says. Some people may experience irritant dermatitis as well, adds Dr. Curran, which can cause a rash and inflammation.
Unfortunately, even after successful treatment, toenail fungus can return. “I stress to my patients the importance of ongoing preventive care and proper foot hygiene to minimize the risk of recurrence,” says Dr. Kopelman.
Is toenail fungus contagious?
Toenail fungus is everywhere—it’s even a part of our skin biome, Dr. Curran says. That means it’s easily contagious. Toenail fungus can spread from one toe to the next, from person to person, from an infected surface, and even through shared items like towels and nail clippers.
Still, while these fungi are all around us, this contagious toenail fungus has easier access to your skin and nails if you:
- Have cuts or abrasions on your toes
- Walk around public areas barefoot
- Have a medical condition that weakens your immune system
“Maintaining healthy skin and applying topical emollient creams to the feet daily can help keep the skin healthy and block the fungus from getting into the skin and nails,” Dr. Curran says.
However, toenail fungus doesn’t usually spread beyond your toes, per the Cleveland Clinic.
Ways to prevent toenail fungus
Now that you know treating toenail fungus infections is a lengthy process, you might be more invested in avoiding one or getting a repeat infection.
Here’s how to keep fungus at bay:
- Keep your feet clean and dry.
- Wear flip-flops or sandals when you’re in warm, moist areas, such as public showers, pools, and locker rooms.
- Put on a clean pair of socks every day, or change socks often if your feet get sweaty.
- Don’t wear tight-fitting shoes or shoes with non-breathable material.
- Allow wet and damp shoes to dry out, or place them on a shoe dryer. You can also sprinkle antifungal foot powder inside the shoe.
- Keep your toenails shorter than the end of your toes, and cut them straight across to avoid sharp angles.
- Moisturize dry skin, so fungus can’t sneak in the dry cracks.
- Sanitize your nail clippers with soap and water, followed by alcohol.
- Choose nail salons that disinfect their tools after each client.
- Ditch any footwear you wore before you were infected, or use an ultraviolet shoe sanitizer to keep fungus from returning.
When to see a doctor
A tiny white or yellowish spot on your toenail without any bothersome symptoms may not point to a toenail fungal infection. But if your toenail changes in appearance or you have pain, it might be a sign of a full-blown toenail fungus infection that needs medical treatment.
Call your doctor if you see these symptoms:
- Nails that become powdery, thick, brittle, or split
- Nail bed shape changes
- Mild or foul odor emitting from the toenail
- Any systemic symptoms such as fever, chills, night sweats, or weight loss
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Sources
- Hannah Kopelman, MD, a dermatologist at Kopelman Aesthetic Surgery and co-founder of DermOnDemand
- Joseph Zahn, MD, a dermatologist at George Washington University Medical Faculty Associates
- Timothy Curran, DPM, MD, FACFAS, a Podiatrist at Tufts Medical Center
- Shari Lipner, MD, PhD, a dermatologist and the Director of the Nail Divison at Weill Cornell Medical Center
- Inflammation & Allergy-Drug Targets: “Onychomycosis: An Updated Review”
- Frontiers in Medicine: “Prevalence and risk predictors of onychomycosis in patients on hemodialysis: an observation, prospective, and unicenter study in Brazil”
- Indian Journal of Dermatology: “Candidal Onychomycosis: Clinicoepidemiological Profile, Prevailing Strains, and Antifungal Susceptibility Pattern–A Study from a Tertiary Care Hospital”
- Infection and Drug Resistance: “Antifungal Selection for the Treatment of Onychomycosis: Patient Considerations and Outcomes”
- Cleveland Clinic: “Toenail Fungus”
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