Nail Varnish and Discoloured Nails: What You Should Know

Pigments in dark or strongly coloured varnish can leave a yellow, orange or brown cast, especially when polish is worn repeatedly or removed roughly. A base coat may reduce staining, but it does not explain every colour change. Fungal infection can cause discolouration with thickening, brittleness or lifting. Nail psoriasis may produce pits, ridges, yellow-red patches or separation. A bruise, medication effect or another nail condition can also alter colour. Removing varnish and allowing the nail to be seen helps a clinician assess the true pattern.

Remove varnish gently and avoid scraping the surface. Leave the nail uncovered for examination, keep it trimmed, and moisturise the surrounding skin if it is dry. Do not share files or clippers. If discolouration remains, arrange assessment rather than starting treatment based on colour alone. A clinician may inspect the nail and test a clipping when [Nail Fungus](/conditions/nail-fungus/) is possible. If psoriasis is suspected, [Nail Psoriasis](/conditions/nail-psoriasis/) may need separate treatment. [Oral Antifungal Treatment](/treatments/medical-dermatology/oral-antifungal-therapy/) is appropriate only when a clinician confirms that route suits the diagnosis and your health.

Arrange a review if colour does not fade after varnish is removed, returns without polish, or comes with pain, thickening, lifting, bleeding or a change in the surrounding skin. Seek prompt assessment for a new dark streak, uneven pigment or a mark that is widening. If you have diabetes or reduced circulation, do not ignore a painful or damaged nail.

Could this be varnish staining, fungus, psoriasis or an injury? Should the nail be tested? Is it safe for me to continue using varnish? What nail-care products should I avoid? Which changes would mean I should return quickly?