Overview
Fungal infections happen when fungi grow on or in the body. Some affect the surface, such as the skin, scalp, nails, mouth, or genitals, while others affect deeper tissues like the lungs. Surface infections are often uncomfortable but limited, while invasive infections can be severe and need prompt medical attention.
Key Symptoms
Symptoms depend on where the infection is. Skin infections may cause itching, redness, scaling, cracking, or a ring-shaped rash; nail infections may cause thickening, discoloration, or crumbling. Oral thrush can cause white patches and soreness in the mouth, and vaginal yeast infections may cause itching, irritation, and abnormal discharge. Deeper fungal infections may cause fever, cough, chest pain, shortness of breath, or feeling very unwell.
Causes and Risk Factors
Fungi are found in soil, on surfaces, on animals, and sometimes normally on the human body. Infection can happen when fungi overgrow, enter through breaks in the skin, or are breathed into the lungs from the environment. Risk can be higher with damp skin, sweating, tight shoes or clothing, recent antibiotic use, diabetes, steroid use, cancer treatment, HIV, organ transplantation, or other conditions that weaken the immune system.
Who Is Affected
Fungal infections can affect people of any age. Surface infections are common in children and adults, especially in hot or humid climates and in people who use communal showers, gyms, or swimming areas. Serious invasive fungal infections are more likely in people who are hospitalized, have major medical problems, or have weakened immune defenses.
Prevention
Keep skin clean and dry, especially between toes, under skin folds, and in the groin area. Avoid sharing towels, shoes, hairbrushes, nail tools, or clothing, and wear sandals in communal wet areas when possible. Change out of sweaty clothes promptly, wash hands regularly, and follow medical advice if you have diabetes or a condition that affects immunity.
Diagnosis and Tests
A healthcare professional may examine the affected area and ask about symptoms, medicines, travel, and health conditions. Diagnosis may involve taking a skin, nail, or mouth sample for microscopy or culture, or using blood tests or imaging for suspected deep infection. Because rashes and irritation can have many causes, getting the right diagnosis is important before treatment.
Treatment Categories
Treatment depends on the type, location, and severity of the infection. Options may include antifungal creams, powders, mouth treatments, or oral or hospital-based medicines for more severe disease. It is important to use treatment exactly as directed by a clinician and to complete the recommended course, because fungal infections can come back or be mistaken for other conditions.
When to Seek Medical Care
Seek medical care if a rash, itching, nail change, mouth soreness, or genital symptoms do not improve, keep returning, or are spreading. Also get medical advice if you have fever, significant pain, trouble swallowing, symptoms in the eyes, or if you have diabetes, are pregnant, or have a weakened immune system. Early assessment is especially important for infants, older adults, and anyone who seems very unwell.
When It May Be an Emergency
Get urgent medical help if there is difficulty breathing, chest pain, confusion, fainting, signs of sepsis, or rapidly worsening illness along with possible fungal infection. Emergency care is also important for severe symptoms after cancer treatment, organ transplant, advanced HIV, or other major immune suppression. A deep fungal infection can become life-threatening if not treated quickly.