Fungal Infections: Causes, Symptoms, and Treatment
Medically reviewed by Sumiran Racherla, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Fungal Infections?
A primary care doctor or a dermatologist (a skin doctor) often treats fungal infections of the skin and nails. An infectious disease doctor (a doctor who treats infections) may help with serious or hard-to-treat infections. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What are fungal infections?
A fungus is a primitive organism. Mushrooms, mold and mildew are examples. Fungi live in air, in soil, on plants and in water, and some live in the human body.
Fungal infections range from mild to life-threatening. Common ones are ringworm, nail infections, and vaginal yeast infections.
Symptoms
Symptoms depend on where the infection is. Ringworm, which is caused by fungi and not a worm, is one common type. On the skin, it causes an itchy, scaly, often ring-shaped rash. The rash typically looks red on light skin and appears gray or brown on darker skin.
Nail infections may cause nails to change colors, become thick, and break easily.
Vaginal yeast infections are caused by overgrowth of a yeast called Candida in the vagina. Some fungal infections affect the lungs. They are caused by breathing in fungal spores from soil or dust.
Symptoms of ringworm are similar to symptoms of other skin or nail conditions. Many fungal infections can also look like more common diseases caused by bacteria or viruses.
Causes and who gets it
Some fungi reproduce through tiny spores in the air. You can breathe in the spores, or they can land on you. Because of this, fungal infections often start in the lungs or on the skin.
People are exposed to fungi every day and most of the time do not get sick. Many people breathe in fungal spores without ever getting sick, but some people develop severe illness.
Candida is a yeast that lives in and on the body. It causes symptoms only when it grows out of control.
You are more likely to get a fungal infection if you have a weakened immune system or take antibiotics. A weakened immune system can come from illness, age, or medical treatments like steroids.
Ringworm spreads in several ways:
- Skin-to-skin contact with people or animals with the infection.
- Shared objects like towels and bedsheets.
- Shared surfaces like locker room or public bathroom floors.
Ringworm risk goes up with tight shoes and socks, heavy sweating, and contact sports such as wrestling.
How doctors diagnose it
Fungal infections are often misdiagnosed, which can delay the right treatment. If you have a rash, a nail infection, or other symptoms of ringworm, go to a healthcare provider for testing.
Providers may take a small skin scraping or nail sample for testing. Testing can help make sure you get the right treatment.
Treatment
Fungal diseases are treated with antifungal medicines. They can be taken by mouth, given through a vein, or put on the skin as creams or ointments.
For skin and nail infections, you can apply medicine directly to the infected area. Oral antifungal medicines are also available for serious infections.
Treatment for ringworm depends on where it is on the body and how serious it is. Some forms can be treated with non-prescription (over-the-counter) antifungal medicines. Other forms need prescription antifungal medicine.
Do not use steroid creams for a rash that could be ringworm. Antibiotics cannot treat fungal infections and can even raise the risk of them.
Fungi are becoming resistant to some antifungal medicines. To help keep them working, take them exactly as prescribed by your healthcare provider.
When to see a doctor
Talk to your healthcare provider if you think you or a loved one has a fungal infection. This matters most if you have a weakened immune system.
Call 911 or go to the emergency room for trouble breathing, chest pain lasting two minutes or more, fainting, or a sudden change in mental state such as confusion.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. A direct primary care doctor can look at a rash or nail change, order or arrange testing, and start or review treatment. They can also refer you to a skin doctor or an infectious disease doctor when needed.
Common questions
Are fungal infections contagious?
Some are, and some are not. Ringworm is very common and can spread through skin contact, shared towels or bedsheets, and shared surfaces like locker room floors. Fungal infections that start in the lungs come from breathing in spores from the environment.
Can antibiotics treat a fungal infection?
No. Antibiotics cannot treat fungal infections and can even raise the risk of them. Fungal infections are treated with antifungal medicines.
Can I treat a fungal skin infection with an over-the-counter cream?
Sometimes. Some forms of ringworm can be treated with non-prescription antifungal medicines, but other forms need prescription medicine. Because the rash can look like other skin problems, ask a healthcare provider before you start.
How can I help prevent fungal infections?
Keeping your skin clean and dry helps. Wear protective footwear in public showers or locker rooms, and change your socks and underwear every day. Do not share sports gear or personal items like towels or socks.
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Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
