Terminal Hair

Terminal hair is the thicker, pigmented, longer hair type that replaces finer vellus hair in certain parts of the body, including the scalp, eyebrows, eyelashes, beard, chest, underarms and pubic region. These hairs originate from larger follicles, contain more pigment-producing cells (melanocytes), and generally have a longer anagen (growth) phase and greater diameter than vellus hair, which makes them more visible and durable.

Hormonal influences—especially androgens—play a major role in the development, distribution and behavior of terminal hair, and changes in terminal hair can signal underlying conditions such as androgenetic alopecia or hirsutism. Clinically, distinguishing terminal from vellus hair is useful for diagnosing hair disorders, tracking progression (for example miniaturization in pattern hair loss) and planning appropriate medical or surgical interventions when needed.