What should you know about white wavy lines on nails?

A white line may follow minor trauma, manicure pressure, picking, or separation within the nail plate. Lines that run across several nails can reflect an interruption in nail growth, while surface ridges or crumbly material may point toward a nail disorder. Nail fungus can cause colour and texture changes, and nail psoriasis can produce ridges, pits, or areas that lift from the bed.

The visible nail records earlier events, so a mark may remain while the nail slowly grows forward. A photograph and a timeline of illness, injury, medicines, or salon treatments can help a clinician interpret the pattern.

Keep nails short and dry, moisturise the surrounding skin, and pause harsh filing, scraping, or nail products until the cause is clearer. Do not prise the nail from its bed or share clippers. If the line persists, affects several nails, or comes with thickening, lifting, pain, or debris, arrange a dermatology review.

A clinician may examine the nail and surrounding skin and may test material if fungus is suspected. Treatment depends on the cause; oral antifungal treatment is considered only when a fungal infection is supported and the medicine is suitable for you.

Seek prompt assessment for a new dark streak, bleeding, a rapidly changing nail, severe tenderness, pus, or redness spreading around the finger or toe. Arrange review sooner if you have diabetes, reduced circulation, or a weakened immune system, because nail or skin infections may need closer management.

Ask whether the lines are in the nail plate or underneath it, whether testing for fungus is useful, and what signs would suggest psoriasis or another nail condition. Mention every affected nail and any recent injury, illness, medication change, or manicure.