Fungal Infection
The immune system usually keeps harmful microorganisms under control, but when fungi multiply excessively, enter through the skin, or spread inside the body, they can lead to fungal infections — also known as mycosis. These infections can range from mild conditions like athlete’s foot to serious, life-threatening illnesses when internal organs are involved. Fungal infections are extremely common worldwide; some are simple to treat, while others demand rapid medical care to prevent serious damage. Understanding their causes, symptoms, and treatment options is key to protecting long-term health and reducing the risk of complications.
What Are Fungal Infections?
A fungal infection (mycosis) occurs when harmful fungi grow on or inside the body. Fungi normally live on the skin, in the air, in soil, and on surfaces. However, when their growth becomes uncontrolled, they can invade tissue and cause infection.
These infections can affect:
Skin
Nails
Hair
Lungs
Mucous membranes (mouth, sinuses, vagina)
Internal organs (in severe cases)
What Are Fungi?
Fungi are microorganisms that include yeasts, molds, and mushrooms. Unlike bacteria and viruses, fungi are eukaryotic organisms, meaning they have a complex cell structure similar to humans. This is one reason fungal infections can sometimes be difficult to treat — many antifungal medicines must target fungi without harming human cells.
What Does a Fungal Infection Look Like?
The appearance varies depending on body area involved. Common signs include:
Red, itchy, or peeling skin
Circular or ring-shaped rashes
Discolored or thickened nails
White patches inside the mouth
Vaginal itching or discharge
Scaly or flaky patches on the scalp
In deep/systemic infections:
Persistent cough
Fever
Fatigue
Unexplained weight loss
Shortness of breath
Who Is Most at Risk for Fungal Infections?
Anyone can get a fungal infection, but the risk increases in people who have:
Weak immune systems
Diabetes
Long hospital stays
Antibiotic or steroid use
Cancer or organ transplant history
HIV/AIDS
Obesity
Excessive sweating
Lifestyle factors can also increase risk:
Sharing towels/shoes
Wearing tight or damp clothing
Walking barefoot in public showers
Poor hygiene
High humidity environments
Are Fungal Infections Serious?
Superficial infections (skin, nails, scalp) are usually mild and treatable.
However, deep or systemic fungal infections can be deadly if untreated — especially in people with weakened immune systems.
What Are the Different Types of Fungal Infections?
Superficial Fungal Infections
These affect the surface of the skin, nails, and hair.
Examples include:
Athlete’s foot
Ringworm
Jock itch
Nail fungus (onychomycosis)
Oral thrush
Vaginal yeast infection
Subcutaneous Fungal Infections
These involve deeper layers of skin and can reach tissues under the skin.
Examples include:
Sporotrichosis
Chromoblastomycosis
These often occur due to fungal spores entering through cuts or wounds.
Deep (Systemic) Fungal Infections
These affect internal organs such as the lungs, brain, or bloodstream.
Examples include:
Histoplasmosis
Aspergillosis
Cryptococcosis
Candidemia (bloodstream infection caused by Candida)
Systemic infections require urgent medical care and can become life-threatening.
What Are the Symptoms of Fungal Infections?
Symptoms depend on the type of infection and the part of the body affected.
Symptoms of Superficial or Subcutaneous Fungal Infections
Red, itchy skin
Circular or ring-shaped rashes
Cracked or peeling skin
Thickened or yellow nails
Scalp scaling or hair loss patches
Vaginal itching or burning
White coating inside the mouth or throat
Symptoms of Fungal Infections in the Lungs
Persistent dry or productive cough
Chest pain
Fever
Fatigue
Difficulty breathing
Night sweats
These symptoms may resemble pneumonia or tuberculosis.
Other Possible Symptoms of Fungal Infections
Headache
Joint or muscle pain
Chills
General weakness
Digestive issues (in systemic infections)
What Causes Fungal Infections?
Fungal infections occur when:
Fungi overgrow normally on the skin or inside the body
Fungal spores enter through wounds or inhalation
The immune system is too weak to control fungal growth
Common contributing factors include:
Moist or humid environments
Tight or sweaty clothing
Antibiotic use (which reduces protective bacteria)
Poor hygiene
Chronic illnesses
Hormonal changes
How Do Fungal Infections Spread?
Fungi spread through:
Direct skin-to-skin contact
Contact with contaminated surfaces (showers, floors, gym equipment)
Sharing clothing, shoes, towels, or personal items
Contact with infected animals
Inhaling airborne fungal spores
Contact with soil in outdoor injuries
Are Fungal Infections Contagious?
Some are contagious, especially:
Ringworm
Athlete’s foot
Jock itch
Nail fungus
Oral thrush
Vaginal yeast infection
Systemic fungal infections do not spread from person to person — they usually develop from inhalation of spores or weakened immunity.
How Is a Fungal Infection Diagnosed?
Doctors may perform:
Physical examination
Skin scraping or nail sample
Microscopic evaluation
Culture test to identify fungus type
Blood test for systemic infections
Chest X-ray or CT scan for lung involvement
Biopsy when deep tissue infection is suspected
Identifying the exact fungus helps determine the most effective treatment.
How Are Fungal Infections Treated?
Treatment depends on infection type and severity.
Superficial infections
Topical antifungal creams, powders, lotions, or ointments
Good hygiene and dryness of skin
Subcutaneous infections
Oral antifungal medications
Surgical cleaning of affected tissue in some cases
Systemic infections
Strong intravenous (IV) antifungal medications
Hospital care for severe lung or bloodstream infections
What Medications Are Commonly Used to Cure Fungal Infections?
Common antifungal medicines include:
Azoles: Fluconazole, Itraconazole, Ketoconazole
Allylamines: Terbinafine, Naftifine
Polyenes: Amphotericin B (often for severe systemic infections)
Echinocandins: Caspofungin, Micafungin, Anidulafungin
Do not stop treatment early — stopping too soon can cause recurrence.
What Can I Expect If I Have a Fungal Infection or Fungal Disease?
The prognosis depends on the type of infection.
Superficial fungal infections usually clear within 2–6 weeks with proper treatment.
Subcutaneous infections require longer treatment and may take months to resolve.
Systemic fungal infections need urgent medical care and ongoing monitoring.
Recovery depends on early diagnosis and overall immune health.
Most fungal infections are treatable, but delays can lead to scarring, hair loss, weakened immunity, bloodstream infection, or life-threatening complications.
How Can I Lower My Risk of Developing a Fungal Infection?
Healthy habits can significantly reduce risk:
Keep skin clean and dry
Wear breathable clothing and cotton socks
Change sweaty clothes promptly
Avoid sharing towels, shoes, and personal items
Wear footwear in public pools and locker rooms
Maintain good management of diabetes
Strengthen immunity with sleep, hydration, and nutrition
Avoid unnecessary antibiotics
Keep pets monitored for skin infections
For high-risk individuals, early screening and preventive treatment may be recommended.
When Should I See a Healthcare Provider?
Contact a healthcare professional if you notice:
Persistent itching, redness, or rashes
Peeling or cracked skin that doesn’t heal
Thickened or discolored nails
White patches inside the mouth
Vaginal itching or unusual discharge
Chronic cough, fever, or breathing difficulty
Symptoms that return after treatment
Seek emergency care if:
Confusion, high fever, chest pain, or severe breathing difficulty occur
These may indicate a systemic fungal infection.
What Questions Should I Ask My Doctor?
What type of fungus caused my infection?
How long will treatment take?
Are there lifestyle changes that can speed recovery?
Can it spread to others in my home?
What should I do if symptoms come back?
Do I need long-term follow-up for this infection?
A Message From Cleveland Clinic
Fungal infections are common, but they do not have to control your life. Early diagnosis, proper medication, and good hygiene can cure most infections and prevent them from returning. If symptoms persist or spread, never hesitate to seek medical care — your health and comfort matter.
With the right support and awareness, you can protect yourself and your loved ones from fungal disease and live confidently, comfortably, and infection-free.