The Two Main Hair Types
04 / 21 / 16

The Two Main Hair Types

Even though different ethnicities have different hair characteristics, there are basically two main hair types.

The two major types of hair follicles on the human body are terminal hair follicles and vellus hair follicles. The terminal hair follicles are larger than the vellus hair follicles and extend into the subcutaneous fat by anywhere from 2-5mm from the skin surface during hair growth.

In contrast, the lowest portions of vellus hair follicles generally extend only into the reticular dermis. Hairs produced by terminal hair follicles are usually at least .06mm in diameter, while vellus hairs are short, fine, and usually less than .03mm in diameter. The term “intermediate hairs” has been used to describe hairs with characteristics that are between vellus and terminal hairs or between .03 and .06mm in diameter.

At birth, terminal hairs are found on the scalp, eyebrows, and eyelashes, and vellus hairs populate the remaining hair-bearing areas. During puberty, vellus hairs in certain areas, such as the genital area and axilla, are stimulated to become terminal hairs.

Transitioning between terminal and vellus hair follicles may also occur in pathological states. Abnormal transitioning of vellus hairs to terminal hairs occurs in hirsutism in women, and transitioning of terminal hairs to vellus hairs, also known as follicular miniaturization, is a classic feature of androgenetic alopecia.

The medical treatments at the Hair Transplant and Restoration Center are centered on transitioning vellus and intermediate hairs back to a terminal state as well as extending the length of the hair cycle.

Low Level Laser Therapy (LLLT) are especially effective at transitioning the vellus and intermediate hair back to a terminal state. There are no “new” hair follicles created, but the density of hair is increased because each miniaturized hair now has a greater diameter, and thus it creates better coverage of the scalp. Once a hair miniaturizes to a diameter less than .04mm it is more difficult to transition it back to a terminal state. This is why it is so important to begin treatments sooner than later.

Schedule a consultation at HT&RC today to learn about your hair restoration treatment options.