Missouri Board of Cosmetology Practice Exam 2025 - Free Cosmetology Practice Questions and Study Guide

Split ends are primarily caused by the degradation of the hair shaft, and heat styling combined with environmental stress is a common contributor to this issue. Heat can raise the cuticle layer of the hair, making it more susceptible to damage. When heat styling tools, such as flat irons, curling wands, and blow dryers, are used frequently without proper heat protection, they can weaken the structure of the hair and lead to split ends.

Environmental stress refers to factors such as pollution, humidity, UV exposure, and changes in temperature, all of which can cause the hair to dry out or become brittle. Combined with the effects of heat styling, these elements can compromise the integrity of the hair, resulting in split ends. Protective measures, such as using heat protectants and limiting the use of hot tools, can help mitigate this damage.

While other options, such as excessive washing or using non-professional hair products, may contribute to hair health issues, they are not as directly linked to the formation of split ends as heat styling and environmental stress.