What should you know about brittle big toe nails?

The big toe takes pressure from footwear and repeated impact, so the nail may crack, split or lift after rubbing or an old injury. Tight shoes, long nails, picking and vigorous filing can keep the damage going. A thickened, yellow or crumbly nail, debris underneath, or scaling between the toes can occur with nail fungus, but these signs are not enough to confirm it. A single damaged nail can also reflect local trauma rather than a wider problem.

Wear shoes with enough room for the toes and keep socks dry. Trim the nail straight across without cutting into the corners, then smooth sharp edges gently. Do not pull off a lifted section or share clippers; clean and dry tools after use. Avoid covering a painful or draining nail with cosmetic products. If the nail stays thick, changes colour or repeatedly breaks, arrange an examination before using medication.

See a clinician if the nail is painful, increasingly separated, thickened, discoloured or surrounded by redness and swelling. Prompt care is needed for pus, spreading warmth, fever, an open wound or a dark streak that does not move outward as the nail grows. Nail Fungus can be discussed when fungal features are present, but testing may be needed because trauma and other conditions can look similar.

Could footwear or an old injury explain this change? Does the nail need testing for fungus or another condition? How should I trim and protect it while it grows? Which symptoms would mean I should return sooner?