Hair Restoration Glossary of Terms

This page contains a glossary of commonly used terms in hair restoration.

5-Alpha-reductaseThe enzyme which converts testosterone to dihydrotestosterone (DHT), the hormone that triggers Androgenic Alopecia in individuals who are genetically susceptible.  Type 1 5-alpha-reductase is found primarily in the skin and Type 2 5-alpha-reductase is found primarily in the prostate and inner sheath of the hair follicle.

AcneAn inflammatory disease which affects the sebaceous glands of the skin.

AlopeciaComplete or partial lack of hair resulting from various conditions.

Alopecia Adnata – Under-development of eyelashes.

Alopecia AreataMedical term for hair loss which occurs in patches on the scalp.

Alopecia SenilisBaldness due to old age.

Alopecia TotalisThe complete loss of scalp hair often combined with the loss of eyebrows and eyelashes.

Alopecia UniversalisThe term for hair loss which occurs over the entire body.

AnagenThe term for the growing phase of the hair cycle which lasts five to seven years in a healthy person.  See catagen and telogen for other phases of the hair cycle.

Androgenic AlopeciaThe common name for male or female pattern baldness which depends on the genetic predisposition of the hair follicles and the levels of androgen (male sex hormone) in the body.

AndrogensMale sex hormones.

AntiandrogenAn antiandrogen blocks the effects of androgens, normally by blocking the receptor sites.

Benign Prostatic Hyperplasia (BPH)Non-cancerous enlargement of the prostate gland.  As the prostate gland swells, it reduces the urine flow and prevents the bladder from emptying.

CatagenThe end of the active growth period of a hair follicle, and is marked by changes in the follicle.  See anagen and telogen for other phases of the hair cycle.

Cicatricial AlopeciaBaldness due to scarring. The follicles are absent in scar tissue.

CloneA group of genetically identical cells or organisms derived from a single common cell.

Coronal grafting (a.k.a. lateral or perpendicular grafts)Grafts are placed into recipient sites made with a very small blade that pierced the skin at right angles to the hair direction. See also sagittal grafting.

CortexThe principal structural component of the hair shaft.

CrownArea at the top of the head.

Dermal papillaThe dermal papilla is situated at the base of the hair follicle.  The dermal papilla contains nerves and blood vessels which supply glucose for energy and amino acids to make keratin.

DHT (5-alpha dihydrotestosterone)A male hormone that is suggested to be the main cause for the miniaturization of the hair follicle and subsequent hair loss.  DHT is formed from the male hormone testosterone by the enzyme 5-alpha-reductase.

Donor SiteSite where hair follicles are harvested during transplant surgery.

Dutasteride A medication for the treatment of benign prostatic hyperplasia (BPH).  It is an inhibitor of type 1 and type 2 5-alpha-reductase, the enzymes responsible for converting testosterone to DHT.

EstrogenOne of a group of hormonal steroid compounds that promote the development of female secondary sex characteristics.

FinasterideFinasteride is the generic name of a drug that binds with the type 2 5-alpha-reductase enzyme to reduce the amount of DHT in the prostate and serum.  Finasteride is approved by the FDA for treatment of benign prostatic hyperplasia (BPH) as Proscar 5mg daily dose and also for hair loss as Propecia 1mg daily dose.

FollicleA tube-like structure in the skin in which develops a hair shaft.

Follicular UnitGroupings of 1-4 hairs that grow together.

Follicular Unit TransplantationA recent technique in hair transplantation where the naturally occurring follicular units of hair follicles are implanted as a natural group.

Gene TherapyA treatment method which involves the manipulation of the genetic makeup.

Generic A term which refers to a substance, product or drug that is non-proprietary (not manufactured and sold only by the owner of the patent, formula, brand name, or trademark associated with the product.)

GynecomastiaExcessive development of the breast tissue on a male.

Hair CloningA technique under development which could make an unlimited crop of donor hair available for transplanting.  It differs from cell therapy, another developing technique in which follicular stem cells are injected directly into the skin to grow new hairs.

Hair Integration Hair weaving.

Hair WeavingA process by which a hair piece is attached to existing hair on the head through braiding or a weaving process.

HirsutismExcessive body or facial hair.

KeratinA collective name for a group of proteins that are present in the hair and nails.

Ludwig ScaleClassification of female pattern hair loss (see Norwood scale).

MedullaThe medulla is a central zone of cells, usually only present in large, thick hairs.

Micro GraftA very small hair graft usually consisting of one or two follicles.

Mini GraftA small hair graft usually consisting of between three to ten hair follicles.

MinoxidilMinoxidil is the generic name of the brand name drug Rogaine.  Minoxidil is a topical lotion available over-the-counter in 2% to 5% solution.  Minoxidil was the first drug to be approved by the FDA for the treatment of androgenic alopecia.

Norwood/Hamilton ScaleThe most commonly used scale for the classification of male pattern hair loss.

PapillaKnoblike indentation at the bottom of the follicle which contains a vascular loop for nourishment.

PropeciaA brand name for finasteride 1 mg, approved for the treatment of male pattern hair loss.

ProprietaryPertaining to a drug that is produced and still under patent by a pharmaceutical company.

ProscarThe brand name for finasteride 5mg, approved for the treatment of benign prostatic hyperplasia (BPH).

Punch GraftPunch grafts are the old fashioned way of removing grafts for hair transplants.  Follicular Unit Extraction (FUE) is a modern adaptation of this technique in which very small punch (1mm or less) is used to re-move one follicular unit at a time.

Recipient SiteThe bald or thinning area into which hair grafts or plugs are transplanted.

Retin-A (Tretinoin)Retin-A is a brand name for a topical gel or cream normally used in the treatment of acne.

RogaineA brand names for minoxidil, a topical lotion for the treatment of hair loss.

Sabaceous GlandSebaceous glands are sebum (oil) producing glands found connected to hair follicles in the skin throughout the body (except in the palms of the hands and soles of the feet).  They deposit sebum on the hairs, and bring it to the skin surface along the hair shaft.

Sagittal Grafting (a.k.a. parallel grafts)Grafts are placed into recipient sites made with a very small blade that pierced the skin parallel to the hair direction.  See also coronal grafting.

Saw PalmettoA plant native to North America.  It may have some, unproven therapeutic benefits for benign prostatic hyperplasia (BPH).  It does not lower DHT or testosterone levels.

Scleroderma A disease of the skin and connective tissue that can cause hair loss over the affected areas.

SebumThe oily secretion of the sebaceous glands of the scalp composed of oils and cellular debris.

SpironolactoneThis drug acts as an antiandrogen and is used in the treatment of androgen related disorders such as female pattern baldness and hirsutism.

TelogenThis is the resting phase of the hair cycle. See anagen and catagen for other phases of the hair cycle.

TestosteroneA predominantly male hormone which promotes the development of male characteristics.

TopicallyMeans to apply directly onto the skin.

Traction AlopeciaHair loss which occurs due to traction being placed on hair.  Traction alopecia is commonly seen with braids, pony tails and other hairstyles which cause tension on the scalp.

TransectionDescribes damage to hair follicles that can decrease survival after transplantation.

TrichotillomaniaA compulsion to pull out one’s own hair.

VellusThe soft downy hair found covering the body.

Vertex (a.k.a whorl)The vertex is the top of the head towards the posterior position, including the area at which the hair grows in a spiral pattern.

4 Responses to “Hair Restoration Glossary of Terms”

  • Dr. YV Rao from Hair Transplant Hyderabad:

    FUE is a method of hair restoration which is missing from the above glossary. I am adding it here:

    Follicular Unit Extraction: FUE is a method of obtaining donor hair for Follicular Unit Transplantation (FUT), where individual follicular units are harvested directly from the donor area, without the need for a linear incision. In this hair restoration procedure, a 1-mm punch is used to make a small circular incision in the skin around the upper part of the follicular unit, which is then extracted directly from the scalp.

    Overall, a one-stop-shop kind of page for all hair restoration glossary. Good work in collecting the information and putting it together/

  • Abel:

    thanks for the great glossary.. I need to see someone about balding and it’s good to have a handle of the vocabulary!!

  • I seen alot of these terms before, but had no idea what they truly meant. Your glossary makes it very easy to understand.

    Someone with hair problems would find this site very informative and helpful if they were looking for a solution for their hair troubles.
    .-= Allen @ Vitamins Nutrition Supplements´s last blog ..Comment Luv, Keyword Luv, Top Commenters, Do Follow =-.

  • Jack:

    That is nice to definitely find a site where the blogger is knowledgable.