What causes trichorrehexis nodosa?

Trichorrehexis nodosa is primarily caused by mechanical damage to the hair shaft. This condition is characterized by the presence of nodular swellings along the hair fibers, which can lead to breakage and split ends. Mechanical damage can occur from various practices, such as excessive brushing, heat styling tools, chemical treatments, and environmental stresses that physically strain the hair.

It is important to understand that while environmental factors can contribute to hair health and the condition of the hair shaft, they do not specifically cause the nodular formations associated with trichorrehexis nodosa. Likewise, fungal infections and allergic reactions pertain to different hair and scalp issues rather than the structural damage indicated by trichorrehexis nodosa. Thus, acknowledging the role of mechanical damage provides the most accurate explanation for the development of this hair condition.