What is a common sign of healthy hair?

A common sign of healthy hair is its manageability. Healthy hair is typically easy to comb, style, and maintain, indicating that it has the right balance of moisture and oil. Manageability reflects the overall condition of the hair, suggesting that it is resilient and can hold styles well without excessive breakage or frizz.

Regarding the other options: split ends are a sign of damage rather than health, indicating that the hair has been subjected to excessive heat, chemical processing, or lack of proper care. A lack of shine often suggests that hair may be dry or damaged, as healthy hair tends to reflect light well due to its smooth, intact cuticles. Low porosity hair may not necessarily equate to health; it refers to the hair's ability to absorb moisture, which can sometimes indicate that the hair is overly porous or damaged, affecting its health. Hence, manageability is a clear indicator of healthy hair.