Illinois Cosmetology Practice Exam 2025 - Free Cosmetology Practice Questions and Study Guide

Excessive heat styling can lead to hair breakage and damage due to the high temperatures that can strip moisture from the hair. This process can weaken the hair's structure, making it more prone to breaking, splitting, and overall deterioration. Hair is made up of a protein called keratin, and when it is exposed to excessive heat, it can cause changes in its physical structure, leading to weakened strands.

The other options do not accurately reflect the consequences of excessive heat styling. Increased elasticity and improved hair shine are typically the results of proper care and hydration, not heat damage. Color retention may also be adversely affected by heat styling, but it is not directly linked to breakage and damage in the same way. Therefore, understanding the impact of heat on hair health highlights why excessive heat styling is detrimental, leading to the problem of breakage and significant damage to hair strands.