What should you know about vertical nail splitting causes?

A lengthwise split may develop when the nail plate becomes dry or repeatedly expands and contracts after contact with water. Picking, biting, manicures, harsh solvents and knocks can create a weak point that travels from the free edge toward the cuticle. The split may affect one nail or several.

Changes in colour, thickness, texture or the skin around the nail can point to a different cause. Nail fungus can make a nail thickened, crumbly or discoloured, although appearance alone cannot confirm it. A clinician may inspect the nail and, when needed, test material before recommending treatment.

Keep nails short and file a snag gently in one direction. Wear gloves for prolonged contact with water or cleaning products, moisturise the nails and surrounding skin, and avoid pulling at the split or covering it with strong adhesive products. Give damaged nails time to grow out rather than repeatedly buffing the surface.

Arrange a routine assessment if the split keeps returning, involves several nails or does not improve with protection. Bring a list of nail products and mention recent trauma, new medicines, skin symptoms or changes in general health.

Seek prompt medical advice for spreading redness, warmth, swelling, pus, bleeding that does not settle, severe pain or a nail lifting after an injury. An isolated dark streak, a mark that widens or pigment extending onto surrounding skin also needs timely review. Do not assume a persistent split is only dryness.

Ask whether the pattern suggests dryness, trauma, infection or another nail disorder, whether a sample is needed, how to protect the nail while it grows, and which changes should trigger a faster review.