What may excess blow drying cause in hair?

Excess blow drying can lead to loss of hair elasticity due to the high temperatures used during the process. When hair is exposed to intense heat, the moisture within the hair strands can evaporate, causing them to become dry and brittle. This lack of moisture directly affects the hair's elasticity, as healthy hair requires a certain level of hydration to maintain its structure and flexibility. When elasticity is lost, hair becomes more prone to breakage and damage, making it important to use blow dryers with caution and to incorporate heat-protectant products when styling. The other options suggest outcomes that are generally not associated with excessive heat application to hair.