Fungus in toenails: what to know

The infection can start at the nail edge and gradually move across the nail. Debris may collect underneath, and the nail can lift from its bed or become uncomfortable in shoes. Athlete's foot may coexist and can help spread fungus to the nail. Trauma, psoriasis, eczema, and other nail disorders can look similar, so colour alone does not establish the diagnosis.

A clinician may examine the nail and test a clipping or scraping before choosing treatment. Topical antifungal treatment is applied directly to the affected nail and may suit limited disease. Oral antifungal treatment reaches the nail through the bloodstream and may be considered when infection is more extensive; your medical history and other medicines matter. Laser treatment is another option discussed in some clinics, while nail surgery is reserved for selected cases. Keep feet dry, change socks when damp, trim nails carefully, and treat coexisting athlete's foot.

Book a medical review if a nail changes colour, thickens, crumbles, or separates and the cause is unclear. Seek earlier care for spreading redness, warmth, swelling, drainage, significant pain, or difficulty walking. People with diabetes, reduced circulation, reduced sensation, or a weakened immune system should have foot and nail changes assessed promptly.

Ask whether the nail needs laboratory confirmation, which treatment fits the number and location of affected nails, how other medicines or liver conditions affect oral treatment, and how to prevent recurrence from skin or footwear.