Hair Transplant Glossary

If you’re unsure about any of the hair loss and hair transplant terms we use on our website or in our clinic, you’ll find clear explanations here. We want you to be fully informed about your hair transplant surgery, so it’s important that you understand everything. If there’s something you can’t find, let us know and we can add it!


Male-pattern hair loss, also called androgenic alopecia, is the most common type of hair loss in men.

According to scientific evidence, 50% of men experience this type of hair loss at some point in their lives.

Androgenic alopecia can also occur in women, but unlike men, hair loss very rarely follows an progressive course to leave a large area of bald scalp. Androgenic alopecia seen in women usually occurs after menopause.

Factors like enlarged prostate, high blood pressure, diabetes, and obesity can cause androgenic alopecia.

However, advanced age and genetic factors are the key factors in male-pattern hair loss.


A densitometer is a tool to measure hair density prior to hair transplant in deciding whether or not a candidate is suitable for hair transplant.

Densitometry is a method that examines the scalp under magnification to obtain information on hair density and follicular unit per square centimeter.

This number helps the surgeon determine how many grafts will be required in the procedure. It also measures the patient’s hair quality (the degree of loss of quality at the hair follicles) and helps predict future hair loss.


Hair grafts, hair follicles, and hair roots are often confused with each other. These concepts are one of the greatest source of confusion when someone begins to consult with a doctor regarding hair transplant surgery.

A hair graft contains a number of different hair follicles and a small amount of skin. In other words, let us say you receive 2500 grafts in hair transplant; it does not mean that 2500 hair roots are transplanted in your donor site, because most grafts usually contain more than one hair root.

While hair grafts and hair follicles mean the same thing, hair root is a different concept.


The donor site, also called donor region or area, is the lower back of the head of the head, where the hair grafts are collected for hair transplant.

The hair in this area is genetically programmed to resist hair loss and so it is least affected from male-pattern baldness. If the donor area fails to produce quality hair for transplant, other regions of the body can be used as a donor site to harvest hair follicles.

As the DK Klinik hair transplant unit, we do not recommend and use any region other than the back of head as donor site because the hair collected from other areas will not have the same character and quality.

During hair transplant surgery, hair follicles are harvested from the donor site and transplanted to the balding areas, which are called recipient sites.


It is an indicator of hair strand thickness. It is determined by measuring the diameter of a hair strand. Thick hair can offer better results and appearance than thin hair.


Each hair root contains around 1 to 4 hair strands and is surrounded by a capsule called root sheath. A follicular unit is composed with the addition of other structures, including a special vein and nerve network, muscles, and sebaceous glands.

Extracting hair strands from a follicular unit and transplanting them individually is not a healthy method. The group of hair in the follicular unit should be transplanted as a group.


In Follicular Unit Extraction (FUE) method, hair transplant surgery involves harvesting hair follicles one by one through a punch biopsy tool from the donor site and transplanting them to the bald areas of the scalp one by one.

In order to produce the desired appearance, the FUE technique should take into account many factors such as several factors such as the number of available grafts, the exit angles and direction of the hair. Contrary to the FUT technique, the FUE does not require a large incision in the scalp. Click here for more detailed information about the FUE method.


In FUT method, unlike the FUE, hair follicles are not harvested from the donor site one by one but in clusters of follicles, or a thick donor strip about 1 to 1.5 cm in width and 10 to 20 cm in length removed from the scalp.

As it is more invasive and requires much larger incision, it leaves larger scars on the scalp. In the FUT method, the hair roots are extracted from the strip one by one using a scalpel.

Therefore, the most obvious difference between the FUE and the FUT is the way the surgeon collects the hair follicles. In modern medicine, the FUT method is gradually abandoned and the FUE method is becoming a more preferred technique.


These are the tiny secretory cavities containing hair roots consisting of 1 to 4 hair strands. A frequently used term in hair transplant industry, hair follicle is often used interchangeably with the term graft, which is described above.

Actually, a graft is composed of a follicular unit and a hair follicle. The hair grows in a hair follicle.


In about 5% of hair transplant patients, a temporary hair loss (in almost all cases) can occur after the surgery.

The hair that sheds after the surgery begins to grow back after 3 months on average. Shock loss is a reaction of the body to the local trauma caused by hair transplant surgery.

It may occur in both FUE and FUT methods. Hair transplants done in inexperienced centers run a higher risk of shock loss.


A punch biopsy pen is a medical instrument used to collect hair follicles from the scalp in hair transplant. The diameter of the cutting apparatus in the tip of the punch biopsy pen can be adjusted according to the donor site.


The macrograft technique is one of the milestones that revolutionized hair transplant because modern hair transplant began with the use of macrograft technique by the dermatologist Norman Orentreich in 1959.

In this technique, the hair roots were harvested from the lower back of head through large punches ranging from 5 to 10 mm and directly transplanted to the recipient sire without any special treatment to the roots. That enabled the transplantation of 8 to 12 hair strands at each time. This technique, which was used before the FUT method, was causing an unnatural looking appearance after the transplant.

In the beginning of the 1980s, there was a development revolutionizing hair transplant scene called micrograft method and it enabled much more natural appearance in hair transplantation. The most common transplant methods of today, the FUE and FUT techniques are in the micrograft category.


The frontal hairline is the point where hair meets the forehead. When designing the frontal hairline, the patient’s facial features should be taken into consideration.

Apart from that, other criteria such as gender, age, amount of hair loss are also important. A correct frontal hairline design by the surgeon prior to the transplant plays a key role in the natural appearance that could be achieved.

Designing a hairline too low or too high on the forehead will cause unnatural appearance.


The Norwood-Hamilton scale is a measurement system used to classify the extent of male-pattern hair loss.

The scale classifies hair loss into 7 types, type 1 being the minimal hair loss and type 7 extensive hair loss. Hair loss at stage 5 or over cannot be reversed or stopped with the existing medications; only a hair transplant could offer a permanent solution.


The Ludwig grading system is a measurement tool used to classify the degree of female pattern hair loss. It differs from the grading system used for the classification of male-pattern hair loss in that it has only 3 stages. Stage I means mild hair loss, Stage II moderate and Stage III extensive hair loss.


An androgenic hormone, DHT (dihydrotestosterone) is a hormone that stimulates the development of male characteristics. Testosterone is converted into DHT hormone by enzymes and DHT hormone plays vital roles in men’s metabolism from adolescence to adulthood.

As men age, the receptors in hair follicles that are sensitive to DHT hormone cause hair to fall off. Men with the same level of DHT hormone may or may not suffer the same degree of hair loss.

This is because of the individual differences in the receptors of this hormone in the hair follicles. In some people, their body responds to this hormone on a higher level so they begin to experience hair loss. The drugs taken to prevent hair loss are intended to suppress the activity of DHT hormone.


Hair follows a specific life cycle with three phases: anagen, catagen, and telogen phases. In anagen phase, the hair features a period of development and rapid growth. When the catagen phase begins the hair stops growing and stays the same for some time. In the telogen phase, the hair is removed from the body.

The hair strands in one region may be in different phases of this cycle. Therefore, some of our hair may be in the anagen phase, while others are in the telogen phase.

Everyone’s hair life cycle is different so the most important factor determining after how long one’s hair grows back following hair transplant is the person’s hair life cycle.


Local anesthesia is a type of anesthesia administered to prevent the patient from feeling pain in small surgical procedures. Prior to hair transplant surgery, the doctor injects local anesthetics into the donor and recipient sites.

After the local anesthesia procedure, the patient remains fully conscious, which significantly lowers the risk of any complications as compared to general anesthesia.


An enzyme that is produced in the male testes (and in the female ovaries). It is responsible for converting the male sex hormone testosterone into another male sex hormone, dihydrotestosterone (DHT).

As men age, this DHT can build up, causing the hair follicles to become sensitive to it. Hair follicles then become increasingly starved of nutrients, they become unhealthy, begin to shrink and then produce increasingly thinner hairs. Follicles on the top and front of the scalp are thought to be more susceptible to the effects of DHT. Eventually, the hair follicles die, and produce no more hairs, resulting in male pattern baldness.


A male sex hormone, for example testosterone, or dihydrotestosterone.


An anacronym that we use to describe our own principles and approach to quality and successful hair transplants at the DK Hair Klinik – Aesthetics, Quality, Improvement, Control & Science.


The same principle that underlies a hair transplant – taking strong and healthy hair follicles from a donor site and transplanting them into an area of less hair growth, the recipient site – but in the lower facial area rather than the scalp. The same method can be applied to the eyebrow or sideburn area of the face. Beard transplants can help beard growth become fuller and thicker, or to fill in patchy thin areas of beard or moustache growth.


Some men with extreme hair loss don’t have enough healthy hair follicles around the back of the scalp to harvest and transplant to balding areas on the top and front of the scalp. New technology is now allowing hair surgeons to take hair follicles from other parts of the body to use on the scalp. Areas such as the arms and legs can be used. However, as this technology is fairly new, it has varying levels of success. Hair follicles on the body tend to be deeper than and have a different orientation to those on the head, and tend to produce shorter, more wiry hairs.


A device that hair surgeons can use to both extract healthy follicular units from the donor site and transplant them back into the recipient site in one action. Normally, surgeons use one tool to extract and then another to implant, or graft. The choi pen has a hollow needle at one end which can safely house the hair follicle during an FUE hair transplant and removes the need to create separate incisions in the recipient site in order to transplant. The choi pen creates the incision and transplants the entire follicular unit at the same time. It’s thought to help reduce the chances of a graft failing to thrive.


The uppermost part of the head and refers to the area of scalp that is commonly susceptible to male pattern hair loss. This pattern of hair loss usually begins at the ‘whorl’, the area of scalp at the centre of the crown, and gradually spreads outwards across the crown in all directions. The hair loss follows a circular pattern across the crown and beyond. The crown is also known as the ‘vertex scalp’.


A medical drug that blocks the action of dihydrotestosterone (DHT) on the hair follicles. Excess DHT causes the hair follicles to shrink and eventually die due to a lack of nutrients, resulting in male pattern baldness. The most effective and well known DHT blocker is a prescription only drug called finasteride. Finasteride is often sold under the brand name, Propecia. There are some natural DHT blockers, namely supplements containing extracts of some or all of the following – pumpkin seeds, green tea, nettle juice and the herb saw palmetto. However, there is little to no scientific evidence to prove that these work well as DHT blockers.


The visible, outermost layer of skin that covers the deeper skin layers called the dermis and the hypodermis. It provides a waterproof barrier and protection from the environment, extremes of temperature and infectious pathogens and controls the amount of water that can leave the body in the form of sweat. Hair follicles are thin tubular pouches within the epidermis that extend downwards toward the inner layers of skin from which hairs grow. The root of each hair is attached to the bottom on the follicle with connective tissue.


A common condition characterised by thinning hair across the top of the scalp from the front hairline backwards towards the crown, or vertex scalp. Thinning might be evenly over the whole area, or in patches. It can be exacerbated by pregnancy or the menopause. Unlike men, women are generally less likely to experience large bald patches and more likely to experience an overall thinning.


A section of tissue from the scalp that includes four or five hair follicles and up to 20 individual hairs. Hair follicles can contain one hair, but most contain tow, three, four or even five.


The area of scalp at the very front, above the forehead. The frontal scalp is the area where those without hair loss can grow a fringe from and makes up the front, or anterior hairline. Male pattern baldness with a ‘receding hairline’ is when hair is lost from the frontal scalp and hairline appears to be moving backwards towards the crown, making the forehead appear larger. It’s extremely common for men to lose at least a small part of their anterior hairline as they grow from boyhood into adulthood.


A theoretical process by which a healthy single hair follicle is removed from the donor site, and cloned, or replicated in the laboratory, thousands of times over. These new, cloned, follicles are then grown under sterile laboratory conditions before being transplanted into the recipient area where hair loss is greatest. At the moment, this process does not yet exist as scientists and researchers are still finding the best way to successfully grow hair follicles in test tubes or petri dishes. But it’s thought that the first successful hair cloning procedure isn’t too far away.


An early type of hair transplant. Hair surgeons would take small, round ‘plugs’ of tissue from the donor area in neat rows using a punch tool. Each plug would contain four or five hair follicles and up to 20 hairs. The surgeon would then create slightly smaller holes in the recipient area for the plugs to be transplanted into. Therefore, when the new hair began to grow back in the recipient area, up to 20 hairs would grow from one small area. This often resulted in rows of doll-like hair growing in clusters, or plugs, especially around the front of the hairline.


The term used to describe the removal of hair follicles, or follicular units, from a donor area of the scalp, usually around the back, and the transplantation of them into the recipient area of the scalp, usually around the front and top. This could be using the hair plug method, FUT or FUE.


The total time from start to finish of a hair transplant. One session will involve the whole process from the harvesting of follicular units, to their preparation for transplantation to transplantation. How many follicular transplants an individual can have in one session will vary and depend on the strength of the donor site and the size of the recipient area. Some may have their entire balding area completed in one session, others may only have gaps to fill, and others may need to return for subsequent sessions.


The process by which hair surgeons remove hair follicles or follicular units from the donor area in order for them to be transplanted into the recipient area. This can be via the FUT or ‘strip harvesting’ method, or the FUE method. FUT generally involves removing a strip of skin from the scalp from which the follicles can be harvested. FUE involves individual follicular units being removed via a punch tool. FUE leaves less scarring and is generally used over FUT.


A sterile, laboratory-made solution that helps extend the life of human tissue that has been temporarily removed from the human body. During a hair transplant, donor follicular units are placed in HypoThermosol to help preserve their life. Traditionally, a saline solution was used, but as hair transplant procedures have progressed, surgeons have found that keeping them at a lower temperature of 2-8°C is better. HypoThermosol works better than saline at preserving tissues at this temperature.


The International Alliance of Hair Restoration Surgeons. The IAHRS is considered the foremost recognisable consumer hair transplant society in the world. To be a member of this society means that a hair surgeon and/or a hair restoration clinic meets a high standard. Members inform their patients of the realistic expectations they can have of a hair transplant and highlight potential pitfalls as well as the benefits.


The International Society of Hair Restoration Surgery. A non-profit global organisation and the leading authority on hair loss and hair restoration. The society provides valuable information to surgeons to help them deliver the best treatment they can, and to patients to allow them to make an informed decision on hair loss surgery, surgeons and clinics.


The main protein constituent of hair. Keratin is a fibrous protein which lays in layers along the length of the hair. It’s in harder, denser layers to the inside of each hair than it is in the outer layers. The outer layers of keratin lay just beneath the hair cuticle.


See, Androgen.


A common drug used to help promote hair growth. Minoxidil is commonly sold in the form of Regaine/Rogaine sprays, lotions or foams that can be applied to the scalp. It’s a vasodilator which means it helps dilate (widen) blood vessels which is thought to help stimulate hair growth.

Minoxidil needs to be used every day for three to four months before new hair growth will be noticeable. At first the hair will be very fine, but it will begin to thicken over time. It’s suitable for use in men and women, but not in women who are experiencing hair loss after giving birth.

If you stop using minoxidil, your new hair growth will stop. Common side effects include scalp itching and irritation, and less commonly include burning, swelling and inflammation. Consult your hair surgeon or other doctor if you have any concerns over side effects from minoxidil.


The motorised tool used to remove follicular units during a FUE hair transplant. Some surgeons use a manual punch for more control, and some switch between the two during a hair transplant procedure. A motorised punch can hold a sharp tip or a blunted tip and again it’s not uncommon for a surgeon to switch between the two. A sharp tip enters the scalp easier, but there is a risk that it could cause damage to the delicate hair follicles. A blunt tip poses less of this risk but can be slightly more painful when entering the scalp.


The area of the scalp which has experienced hair loss and will be receiving new follicular units. It is usually on the top and front of the scalp and/or along the front hairline.


See, Minoxidil


A process used in FUT method hair transplants. A strip of skin, usually 1 to 1.5cm in width is removed from the scalp, usually from ear to ear around the back of the scalp. Hair follicles are then removed by skilled staff looking through a microscope in order for them to be separated, sorted and transplanted into the recipient site. This method leaves behind a long, thin scar and is less favoured now that more advanced FUE method has developed.


The area of scalp that covers the temples. The temporal scalp is found either side of the frontal scalp and hair loss can begin in these regions and move backwards. It’s common for men to lose hair from these areas whilst the hair on the frontal scalp more or less stays where it is, so called bitemporal recession.


A male sex hormone, or androgen. Testosterone is converted into dihydrotestosterone (DHT), another male sex hormone, by the enzyme alpha 5 reductase. A build up of DHT can cause hair follicles to be starved of nutrients, causing them to shrink and produce thinner, weaker hairs. Affected hair follicles then eventually die and can produce no more hairs.


See, Crown.