Can someone help me with this question because I am really stuck. I understand why a nail peels (over filing, dry, chemicals etc) but I need to know why do nails tend to peel at the top of the free edge, rather than the underneath?

Most anything that is made up of layers will start to break up on the surface rather than from the bottom where there is more stability.

Age and dehydration are is the main factors in peeling nails. The free edge is the oldest and driest part of the nail plate and takes the most impact from daily wear and tear. HTH

Hi first time on forum - thank you for information