Minnesota Cosmetology State Practice Exam 2025 - Free Cosmetology Practice Questions and Study Guide

Damaged hair is generally more porous due to its altered structure. When hair is damaged, the cuticle—the outer protective layer—becomes compromised, allowing moisture, chemicals, and other substances to penetrate more easily. This increased porosity often results from factors such as over-processing, heat damage, and environmental stressors, making the hair more vulnerable to further damage and less able to retain moisture.

In contrast, healthy hair has a smooth cuticle that lies flat, effectively repelling moisture and preventing excessive absorption. Coarse hair tends to be less porous than fine hair because its thicker individual strands can create a barrier, leading to lower porosity. Fine hair, while it can be more porous than coarse hair, does not typically have the same level of porosity as damaged hair, which has an already compromised structure. Therefore, damaged hair's condition leads to higher porosity compared to the other hair types mentioned.