About this condition
Onychomycosis is a fungal infection of a fingernail or, more often, a toenail. Nail thickening, crumbling or discolouration can develop slowly, sometimes without pain.
What to know
Yellow, white or otherwise altered nails do not prove fungal infection. Trauma, psoriasis, age-related changes and other skin conditions may look similar, so a photograph or nail colour is not enough for a diagnosis.
Symptoms and reasons for assessment
One or more nails may thicken, become brittle, change colour or lift from the nail bed. Skin scaling between the toes can occur at the same time, while severe thickening may become uncomfortable in shoes.
Other possible causes
Psoriasis and previous injuries are important alternative explanations. Treating every yellow nail with antifungals can delay appropriate care. A skin scraping test does not automatically mean that sampling and testing a nail is the same service.
How clinicians assess the problem
The dermatologist assesses the number and extent of affected nails and checks for associated skin conditions. A nail specimen for microscopy or another laboratory method may be requested when indicated. Medicines and health conditions matter before any oral treatment.
Treatment and follow-up options
The type and length of treatment depend on confirmed diagnosis, extent of involvement and contraindications. Topical or systemic antifungals may be considered under medical supervision. Nails grow slowly, so visible improvement takes time; avoid taking prescription tablets without assessment.
When urgent care is necessary
Increasing pain, pus, marked redness or swelling around the nail, or fever requires prompt medical care. People with diabetes, circulation problems or immune deficiency should seek care early for inflamed toes. Call 103 for emergencies.
Related health information
Signs and symptoms
Diagnosis and tests
Care and treatment approaches
When to seek urgent care
Frequently asked questions
Is every yellow or thick nail a fungal infection?
No. Trauma, psoriasis and other causes can look similar; laboratory confirmation may be needed.
Why can nail fungal treatment take so long?
Nails grow slowly, and damaged sections must grow out even after infection is controlled.
Can I take antifungal tablets without examination?
No. Diagnosis, contraindications and possible medicine interactions need to be checked first.
Important information
A medical consultation is needed for diagnosis and treatment recommendations.
Self-treatment can be harmful to your health.
