Understanding Hair Growth: How Hair Grows, What Influences It, and What You Can Do

Hair growth is a cyclical, genetically programmed process in which follicles transition through growth, regression, and rest phases to produce continuously renewed human hair. Each strand originates in a follicle within the dermis, where tightly packed keratinocytes form the hair shaft as cells are pushed upward from the dividing bulb at the base. The pace and quality of growth are shaped by genetics, hormones, age, nutrition, health status, and external care practices, while the hair fiber itself reflects cumulative influences from both internal physiology and external grooming. Understanding these mechanisms supports informed expectations and practical strategies for maintaining healthy-appearing hair and scalp.