Ridged toe nails, also known as folded up toe nails, are a type of toe nail deformity that may impact individuals of all ages and sexes. This condition is usually described as the appearance of several transverse folds or indentations on top the toenail. https://articlebiz.com/article/1052041687-what-are-plicatured-toe-nails-and-what-can-be-done-about-them