Brown spots on toenails: what to know

A bruise can appear after tight shoes, a stubbed toe, running, or another injury and may gradually move toward the nail edge as the nail grows. Brown colour can also come from fungal nail changes, old blood, topical products, or increased pigment in the nail. A clinician looks for whether the colour is a narrow line or broad patch, whether it involves the skin beside the nail, and whether the nail is thick, cracked, or lifting. A photograph taken in good light can help you compare change over time.

Remove pressure from the toe with roomy footwear and avoid scraping, drilling, or applying bleaching products to the nail. Keep feet clean and dry, change damp socks, and do not share nail tools. If the mark followed an injury, note when it appeared and whether it travels outward with growth. Arrange a dermatology assessment before using antifungal treatment when the diagnosis is uncertain; a clinician may inspect the nail and surrounding skin and take a small sample if infection is suspected.

Book a prompt appointment if a new dark mark has no clear injury, becomes wider or uneven, changes colour, reaches the skin around the nail, or stays fixed while the nail grows. Seek urgent care for severe pain, spreading redness, warmth, pus, fever, or an injured toe that looks deformed. These signs need assessment because infection and other nail disorders require different treatment.

Ask: Could this be a bruise, infection, or pigment change? Does the colour move with nail growth? Should the nail be tested before treatment? What changes should prompt an earlier review?