What is a common cause of hangnails?

Hangnails often occur when the cuticle area becomes dehydrated or is subjected to trauma, such as from excessive biting. Dehydrated cuticles lose elasticity, making them more prone to splitting and tearing, which is how hangnails typically form. This situation can be exacerbated by environmental factors such as dry weather or insufficient hydration.

Excessive filing might contribute to nail damage, and improper nail polish removal can lead to weakened nails, but these are not direct causes of hangnails. Similarly, wearing tight shoes pertains to foot care rather than nail and cuticle health. Thus, the connection between dehydrated cuticles and hangnails is clear, making it the correct answer.