Overview

Onychomycosis is a common fungal infection that affects your fingernails or, more often, your toenails. It can cause your nails to become discolored, thickened, and crumbly at the edges.

It's caused by different types of fungi (similar to those that cause athlete's foot) that thrive in warm, moist environments. These tiny organisms can invade your nail through tiny cuts or separations between your nail and nail bed.

While anyone can get a fungal nail infection, it's more common in older adults. People with certain health conditions like diabetes, poor blood circulation, or a weakened immune system are also more susceptible. Athletes or people whose feet are often damp can also be at higher risk.

Yes, onychomycosis can be contagious. The fungi can spread from one person to another through direct contact or by sharing items like towels, nail clippers, or shoes. It can also spread from one of your nails to others, or from contaminated surfaces like shower floors or pool decks.

Living with onychomycosis can be frustrating and sometimes make you feel self-conscious about the appearance of your nails. In some cases, if the nail becomes very thick or deformed, it can cause pain or discomfort, especially when wearing shoes or walking.

Symptoms

You might notice one or more of the following signs if you have onychomycosis:

• Discoloration of the nail - This is often one of the first signs. The nail may turn whitish, yellowish, or brownish, often starting as a spot under the tip.
• Thickening of the nail - The infected nail may become noticeably thicker than your other nails, making it difficult to trim.
• Brittle, crumbly, or ragged nails - The nail might break easily or have a powdery surface.
• Change in nail shape - The nail may become distorted or misshapen.
• Debris build-up under the nail - You might see dark-colored material collecting beneath the nail plate.
• Separation of the nail from the nail bed (onycholysis) - The infected part of the nail may lift up from the skin underneath.
• A slightly foul odor may come from the infected nail in some cases.
• Pain or tenderness in the affected finger or toe, especially if the nail is very thick or pressing into the skin, though many infections are painless at first.

Diagnosis

How is it diagnosed? A doctor, often a dermatologist (a doctor specializing in skin, hair, and nails), can usually suspect onychomycosis by examining your affected nail(s). They'll look at the appearance and ask about your symptoms.

Common tests or procedures: To be sure it's a fungal infection and not another condition, and to find out which type of fungus is causing the problem, your doctor will likely take a small sample from the affected nail. This might involve gently scraping some debris from under the nail or clipping off a small piece of the nail. This sample is then sent to a laboratory to be examined under a microscope or to be cultured (allowing any fungi present to grow so they can be identified). This confirmation is important because other conditions can sometimes look like a fungal infection.

Duration & Outlook

Onychomycosis typically develops slowly, often over months or even years. It's generally a chronic condition, meaning it tends to last for a long time and rarely goes away on its own without being addressed.

If not managed, the infection can worsen over time. It may spread to involve more of the nail, other nails, or even the surrounding skin (like causing athlete's foot). The nail can become more discolored, thicker, and more misshapen, potentially leading to pain or difficulty with activities.

Warning signs for complications include increasing pain, redness, swelling, or warmth in the skin around the nail, or any pus draining from the area. If you have diabetes or a weakened immune system, you should be especially vigilant, as you're at higher risk for complications like a bacterial skin infection (cellulitis).

Prevention

Taking good care of your nails and feet can help prevent onychomycosis. Here are some steps you can take:

• Keep your hands and feet clean and dry - Wash them regularly and dry them thoroughly, especially between your toes.
• Wear socks that absorb sweat (like cotton, wool, or moisture-wicking synthetic fabrics) and change them daily, or more often if your feet sweat a lot.
• Choose shoes made of breathable materials - Allow your shoes to air out completely between wearings.
• Wear waterproof sandals or shower shoes in damp public places - Like locker rooms, public showers, and around swimming pools.
• Trim your nails straight across, keep them relatively short, and gently file down any thickened areas - Sanitize your nail clippers and files regularly.
• Don't share nail clippers, files, shoes, socks, or towels with other people.
• If you visit nail salons, ensure they use properly sterilized instruments for each client - You can even bring your own.
• If you have athlete's foot, address it promptly - To prevent the fungus from spreading to your toenails.

Causes & Triggers

What causes it? Onychomycosis is caused by microscopic fungi. The most common culprits are dermatophytes (the same fungi that cause athlete's foot and ringworm). Yeasts (like Candida) and molds can also cause nail infections. These fungi can enter the nail through tiny, often invisible, cuts in the skin around the nail, cracks in the nail itself, or when the nail separates slightly from the nail bed.

Common triggers and how to avoid them:

• Moist environments - Fungi thrive in warm, damp places. Prolonged exposure to moisture (e.g., sweaty shoes, wet work environments) is a major trigger. Avoid this by keeping feet dry and wearing breathable footwear.
• Nail injury - Trauma to the nail, even minor, can create an opening for fungi to enter.
• Poor foot hygiene - Not washing and drying feet properly can create a favorable environment for fungi.
• Walking barefoot in communal areas - Places like gym locker rooms, public showers, and pool decks are common sources of fungi. Protect your feet by wearing footwear.

Who is most likely to develop it?

• Older adults - As we age, blood flow to the extremities can decrease, nail growth slows, and we've had more years of potential exposure to fungi.
• People who sweat heavily.
• Individuals with a history of athlete's foot.

Risk factors:

• Having diabetes, as it can affect circulation and the body's ability to fight infection.
• Conditions that cause poor blood circulation (like peripheral artery disease).
• Having a weakened immune system (e.g., from HIV/AIDS, chemotherapy, or immunosuppressant medications).
• A history of nail injury or nail surgery.
• Wearing artificial nails or nail polish for extended periods without a break can sometimes trap moisture.
• Living in a warm, humid climate.

When to see a doctor:

It's a good idea to see a doctor if you notice any changes in your nails that concern you. Specifically, look for:

• Changes in nail color (white, yellow, brown, or blackish streaks or patches).
• Thickening, brittleness, or crumbling of the nail.
• The nail separating from the skin underneath.
• Pain, redness, swelling, or tenderness around the nail.
• A foul odor from the nail.
• If you have diabetes, it's especially important to see your doctor promptly for any nail problem, even if it seems minor, due to the increased risk of complications.
• If self-care measures for suspected athlete's foot aren't helping, as this could spread to the nails.

How to know when to see a dermatologist: While your primary care physician can often diagnose and discuss onychomycosis, a dermatologist is a specialist in skin, hair, and nail conditions. You might want to see a dermatologist if:

• You want a confirmed diagnosis.
• The condition is causing you significant discomfort or affecting your daily life.
• The infection is severe or involves multiple nails.
• You have an underlying health condition (like diabetes or a weakened immune system) that could complicate things. A dermatologist can accurately diagnose the condition, identify the specific type of fungus, and discuss all appropriate management options with you.

Frequently Asked Questions (FAQs):

Q: Will onychomycosis go away on its own?

It's very rare for a fungal nail infection to clear up on its own. Usually, it's a persistent condition that may worsen or spread if not addressed.

Q: Is onychomycosis painful?

Often, it's not painful in the early stages. However, as the nail becomes thicker or more deformed, it can cause discomfort, tenderness, or pain, especially when pressure is applied, like from wearing shoes.

Q: Can I get onychomycosis from a nail salon?

Yes, it is possible. If tools like clippers, files, or footbaths are not properly sterilized or cleaned between clients, fungi can be transmitted. It's important to choose salons that follow strict hygiene practices.

Q: If I have athlete's foot, am I more likely to get a fungal nail infection?

Yes, very much so. The same types of fungi that cause athlete's foot (a fungal infection of the skin on your feet) can spread to your toenails. Addressing athlete's foot quickly is important.

Q: Can I hide onychomycosis with nail polish?

While nail polish can temporarily cover the appearance of an infected nail, it can also trap moisture underneath, which might create a more favorable environment for the fungus to thrive. It's generally best to avoid regular cosmetic polish on infected nails or to discuss it with your doctor.