Why do toenails curl under the nail sides?

Toenails can curl under the sides due to several factors, including improper nail trimming, fungal infections, or a condition known as ingrown toenails. Genetics may also play a role, as some individuals are predisposed to curved toenails. Additionally, wearing tight footwear can exacerbate the issue by applying pressure to the nail edges. Maintaining proper nail care and wearing well-fitting shoes can help prevent this condition.