Glossary of Terms for Hair Loss & Hair Restoration
5-ALPHA REDUCTASE: An enzyme that converts Testosterone to Dihydrotestosterone (DHT), which is the most important hormone causing genetic hair loss (AGA). There are 2 types, cleverly named Type 1 and Type 2.
ALOPECIA: The medical term for hair loss. Common types include: Androgenetic Alopecia, Traction Alopecia, and Alopecia Areata but there are many more.
ALOPECIA AREATA: A type of hair loss that is believed to be do to a malfunction of the immune system. Typically round or oval bald patches develop suddenly. Usually but not always patients have a full recovery within 6 months. Some medical treatments can help.
ANAGEN: The growing phase of the hair follicle that typically lasts 2-4 years for scalp hairs.
ANAGEN EFFLUVIUM: A sudden shedding of growing hairs caused by a severe stress (like Cancer Chemotherapy)
ANDROGENS: So-called male hormones that both men and women have. DHT is the most important Androgen in Genetic Hair Loss.
ANDROGENETIC ALOPECIA (AGA): The most common cause of hair loss. See Also “Male Pattern Baldness” or “Female Pattern Baldness”. People with AGA inherit genes from either side of the family that make certain hair follicles sensitive to normal levels of Androgens. Affected hair follicles have an altered hair growth cycle and make shorter and finer, miniaturized hairs that don’t cover the scalp as well.
ALOPECIA REDUCTION: A procedure that removes an area of bald skin and stretches hair-bearing skin closer together. A few doctors still perform Alopecia Reductions but, for many reasons, Dr. Simmons and most other hair transplant doctors don’t. Also called “Scalp Reduction.” Some doctors use Extenders or Expanders to allow them to remove a bigger piece of bald skin.
AVODART: Brand of Dutasteride that is not yet approved for treatment of hair loss.
COW-LICK: A Whorl in the anterior hairline is called a cow-lick. It can make it difficult to style hair but it can also make someone’s hairline unique.
CORONAL ORIENTATION: Anatomically, “Coronal” technically means in a side-to-side direction in reference to the head. By common usage in hair transplantation, coronal orientation is related to the hair direction. See “Orientation”.
CROWN AREA: The area in the top/back portion of the head also known as the vertex. Within the crown, there is the transition point and 1 or 2 whorls.
COVERAGE: The size of the area that is transplanted. For a fixed number of grafts, increasing the coverage, causes a decrease in the density. For a given number of grafts, the hair transplant doctor must balance the density and coverage.
DENSITY: The amount of hair in a given area. When transplanting hair, the desired coverage and density must be balanced for a given number of grafts. Increasing one will decrease the other.
DFU (DOUBLE FOLLICULAR UNIT): A graft that contains 2 follicular units. A type of MUG. Some doctors use these in certain areas but Dr. Simmons feels that follicular unit grafts can provide more natural results.
DHT (DIHYDROTESTOSTERONE): DHT is the most important Androgen causing Androgenetic Alopecia. Testosterone is converted to DHT by 5-alpha reductase and this process can be blocked by medications like Finasteride or Dutasteride. DHT has the most effects on the skin, hair, and prostate gland
DONOR AREA: The “Horseshoe-shaped” fringe above the ears and around the back of the head where hair follicles are genetically programmed to last and not to be affected by AGA.
DONOR DOMINANCE: The concept that hair follicles maintain their characteristics when transplanted so that hair follicles from the donor area will still not be affected by DHT and will continue to grow after they are transplanted into the recipient area.
DONOR SCAR: removal of an elliptical strip of donor hair results in a narrow scar. Current techniques can leave behind a narrow scar with hair growing through it.
DUTASTERIDE: Blocks both types of 5-alpha reductase. Avodart is the brand name but it is not yet approved for treatment of hair loss.
FEMALE PATTERN BALDNESS: see “Androgenetic Alopecia”. In many women and some men with “female pattern loss”, exposure to DHT or Androgens causes gradual shrinking of hairs made by genetically- sensitive hair follicles. Affected individuals can get thinning throughout the top of their head without going completely bald. There can be some sparing of the front hairline and the area behind the hairline may be affected the most. There is usually a “horsehoe-shaped” area around the sides and back of the head where the hair follicles aren’t affected.
FINASTERIDE: Propecia and Proscar are brands of Finasteride. Finasteride tablets should be taken daily and are 1 of 2 approved and proven medical treatments to slow hair loss. Finasteride blocks Type 2 5-alpha reductase to reduce DHT levels and reduce the negative influence on hair follicles.
FLAP SURGERY: Older technique where sections of bald skin were removed and flaps of hair-bearing skin were cut and rotated to cover the defect. Dr. Simmons would not recommend this as a procedure of first choice.
FOLLICULAR UNIT: A follicular unit is a natural grouping of one, two, or three (and rarely, four or more) hair follicles. The average follicular unit contains about 2.3 hairs.
FOLLICULAR UNIT EXTRACTION (FUE): Follicular Unit Extraction is a method of removing follicular unit grafts from the donor area, one at a time. A small circle is cut around the graft and the graft is pulled away from the skin. The hole that is left will heal and shrink and form a tiny dot scar.
FOLLICULAR UNIT GRAFT: A graft that contains one follicular unit. As these grafts contain natural bundles of hairs, when artistically transplanted, follicular unit grafts are the best building blocks for natural looking hair transplants.
FOLLICULAR UNIT TRANSPLANTATION (FUT): A method by which large numbers of follicular units are transplanted into a recipient area, one at a time. The grafts are usually harvested from the donor site (usually in a long strip or ellipse) and then microscopically dissected into grafts containing single follicular units. FUE grafts may also be used for follicular unit transplantation.
FRONTAL AREA: The area from the (frontal) hairline to a line that joins both ears. This is usually the most critical area to have hair because it is the area that is observed most face-to-face, in photographs, or in the mirror.
FRONTAL HAIRLINE: The leading edge of hair in the frontal area. A natural (frontal) hairline has a soft transition to denser hair and has an irregular shape. A transplanted hairline that mimics a natural hairline goes a long way toward making a hair transplant hard to detect.
FRONT to TEMPORAL RECESSIONS: The corners between the Frontal Hairline and the Temporal Hairlines. Most men develop distinctly angled FT recessions by the time they are 30, whether they will go on to develop AGA or not. Filling in the FT Recessions for a man can temporarily give a more youthful look but it can look quite unnatural with age and further hair loss. Dr. Simmons recommends transplantation to maintain natural mature Front to temporal Recessions for men. Women and children often do not have distinct Front to temporal Recessions so their hairline design is quite different.
GENETIC HAIR LOSS: see Androgenetic Alopecia.
GRAFTS: Groupings of hair follicles that are transplanted into individual recipient sites. In the past, large round grafts of plugs of 18-30 hairs were used. The next refinement was to use minigrafts, which have 3-8 hairs. Follicular unit grafts are the grafts of choice and contain 1 natural bundle, usually of 2,3, 1 hairs.
GROWTH CYCLE: Hair follicles typically make the hair shaft grow about ½ inch per month for 2-4 years then rest for 2-4 months before making a new hair grow. The old hair tends to rest until it is shed when a new hair grows. The growth phase is called Anagen, the resting phase is called Telogen and the 2-4 week transition phase between Anagen and Telogen is called Catagen. It is not confirmed but the phase of hair shedding may be more complicated than originally believed and may become known as the Exogen phase.
GUTTERS: If someone develops bald areas between their transplanted hair and their natural hair on the sides because of progression of hair loss, they are said to have developed “Gutters”. Gutters do not always develop but particularly for young men, it is important to keep some hair reserved for the future in case they develop gutters.
HAIR ANGLE: Hair exits the scalp at different angles in different parts of the scalp. Matching the angle of the transplanted hair to the natural angle is essential in a natural-looking hair transplant.
HAIR DIRECTION: Hair grows in different directions in different parts of the scalp but there is a flow to hair so that the directions are unified in a pattern. Matching the direction of the transplanted hair to the natural direction is essential in a natural-looking hair transplant.
HAIR FOLLICLE: The complicated “factory” that makes the hair shaft grow. Hair follicles go through growth and resting cycles. See “Growth Cycle”
HAIR TRANSPLANT: A surgical technique that transfers hair follicles from the donor area to the recipient area. Older methods would use “Punch” or “Standard” grafts containing 18-30 hairs, or “minigrafts” containing 3-8 hairs, but follicular unit transplantation of natural bundles of mostly 1 to 3 hairs is now the preferred method.
HAIRLINE REFINEMENT: Hairline Refinement or “Hairline Correction” refers to the use of a variety of newer, more delicate grafting techniques to alter, camouflage or soften the “pluggy” looking results of older hair transplant techniques.
LATERAL HUMPS: These are the bumps on the donor fringe above the ears that are lost when someone progresses from a Norwood 6 pattern to a Norwood 7 pattern of hair loss.
MALE PATTERN BALDNESS: see “Androgenetic Alopecia”. In many men and some women with “male pattern loss”, exposure to DHT or Androgens causes gradual shrinking of hairs made by genetically- sensitive hair follicles. There is a tendency for hair loss to start in the front, the crown, or both and hair loss can go on to affect the entire top of the scalp. There is usually a “horsehoe-shaped” area around the sides and back of the head where the hair follicles aren’t affected.
MICROGRAFT: Before follicular unit grafts were microscopically dissected or extracted, small grafts containing 1, 2, or 3 hairs were made when larger grafts were split.
MIDSCALP: Also called the top, this is the area between the front and the crown.
MINIGRAFT: A graft containing 3 to 8 hairs.
MULTI-UNIT GRAFTS (MUG): Grafts that contain two or more follicular units in a single graft. This term replaces the older “minigraft”. Some doctors still use MUGs in certain areas but Dr. Simmons feels that using only follicular unit grafts gives more natural results without having to sacrifice density.
ORIENTATION: The hairs in a follicular unit are sometimes side-by-side. The surface of a follicular unit may be longer in one direction. There can be confusing terms for the orientation of a transplanted follicular unit but when the hairs are placed front-to-back in the direction of the flow of hair, the graft can be said to have a parallel or sagittal orientation. When the hairs are placed side-to-side across the direction of the flow of hair they can be said to be in a perpendicular or coronal orientation. For natural placement of grafts, Dr. Simmons and many other doctors believe that proper DIRECTION and ANGLE are more important than ORIENTATION.
PARALLEL ORIENTATION: See “Orientation”. Follicular Unit Grafts are placed so the longest direction of the surface of the graft is in-line with the direction of the hair in that area. Also called Sagittal Orientation.
PERPENDICULAR ORIENTATION: See “Orientation”. Follicular Unit Grafts are placed so the longest direction of the surface of the graft is at right angles to the direction of the hair in that area. Also called Coronal Orientation.
“PLUGS”: A slang term typically used to describe the large round grafts that were used more commonly years ago. PLUG is a 4-letter word that should not be used to describe modern follicular unit grafts.
PROPECIA or PROSCAR: Brands of Finasteride.
RECIPIENT AREA: The area to which grafts are transplanted.
ROUND GRAFT: Round, punch, or standard grafts were used from 1959 to the late 1980s. A circle of skin containing 18-30 hair follicles was placed into a hole created by the removal of a smaller circle of bald skin. Before donor strip excision and follicular unit transplantation became the norm, doctors started sectioning round grafts into smaller grafts and transplanted the smaller grafts into smaller incisions.
SAGITTAL ORIENTATION: Anatomically, “Sagittal” technically means in a front-and-back direction in reference to the head. By common usage in hair transplantation, sagittal orientation is related to the hair direction. See “Orientation”.
SCALP REDUCTION: A procedure that removes bald scalp and brings the edges of hair-bearing scalp closer together. A few doctors still perform Scalp Reductions but, for many reasons, Dr. Simmons and most other hair transplant doctors don’t. Also called “Alopecia Reduction.”
SCALP ROTATION FLAPS: A type of procedure that involves removing bald skin and cutting out a flap of skin and rotating it to cover the gap. Dr. Simmons does not recommend this as a procedure of first choice.
TELOGEN: The resting phase of the hair follicle growth cycle that typically lasts for 2-4 months. Transplanted hairs will typically enter a Telogen phase for 2-4 months so that few results will be appreciated for the first few months after a hair transplant.
TELOGEN EFFLUVIUM: A stress on the hair follicles can cause the growth cycle to shift so that many hairs enter the Telogen phase at the same time. Noticeable shedding can ensue within weeks of the stress. Stresses may include childbirth, a major operation, and changing medications like oral contraceptives. Usually Telogen Effluvium is short-lived and full recovery occurs within 6 months. Telogen Effluvium combined with AGA can give rise to a step-wise hair loss with incomplete recovery after an episode of acute shedding. Rarely Chronic Telogen Effluvium occurs and continuous shedding results.
TEMPLES/TEMPORAL AREA: The hair-bearing area on the sides of the head, in front of the ears. These areas can be affected by genetic hair loss.
TEMPORAL POINT: The two triangular shaped areas of hair on the sides of the head that project forward from the sideburns.
TISSUE EXPANDER: This balloon-like device can be inserted under the skin and gradually filled with fluid to stretch the skin to allow excision of a larger portion of balding scalp. This is a valuable technique for patients with hair loss due to burns or trauma but is not a first choice treatment for AGA.
TISSUE EXTENDER: A device that is inserted under the skin and left in place to stretch the scalp and allow excision of a larger area of balding skin. Dr. Simmons does not recommend scalp reduction as a first choice treatment for AGA.
TRACTION ALOPECIA: Hair loss that is caused by repetitive pulling on the hair roots. Often tight braids, ponytails, or top-knots are the cause. Traction Alopecia can be treated by hair transplantation.
TRANSITION POINT: The point at the back of the head where the skull changes from being mostly horizontal to mostly vertical. Hair transplanted behind this point tends to hang down and stay in place better to cover thinner areas behind it.
VERTEX AREA: See “Crown Area”
WIDOW’S PEAK: This is the central triangular projection of hair below the frontal hairline. Dracula had a very pronounced Widow’s peak.
WHORL: An area in the crown or vertex where the hair direction tends to flow away from a central point. Hair flows in a clockwise direction in an “S-whorl” and in a counter-clockwise direction in a “Z-whorl”. Some have double S-Z, Z-S, S-S, or Z-Z whorls.