Hair Glossary – Hair Loss Glossary
ALOPECIA: The medical term for baldness. Alopecia can be temporary or permanent. It occurs due to heredity, diseases, functional disorders or traumas.
ALOPECIA AREATA: Alopecia Areata is an auto-immune disease, clinically described as appearance of completely bald areas of the scalp, while skin is preserved intact. Can be of hereditary, psychological or immunological origin. In case all hair of scalp and face are lost it is called Alopecia Totalis and when hairs are lost from all the body it is called Alopecia Universalis.
ANAGEN EFFLUVIUM: Anagen Effluvium can be experienced as sudden hair loss due to chemical or toxic effect or even radiation – e.g. chemotherapy. Hair loss is observed 1 to 3 weeks after the exposure to one of the previous factors. In most cases, hair regrows when the cause of Anagen Effluvium ceases.
ANDROGENETIC ALOPECIA: The most common type of male hair loss, is responsible for the 95% of alopecia cases. It also affects women though with differences compared to men (FEMALE PATTERN HAIR LOSS). It occurs due to the long-lasting impact of androgens to hair follicles with hereditary predisposition to hair loss.
ANDROGENS: Androgens are hormones produced in men and in smaller quantities in women. In men, androgens are responsible for the characteristics of virility. The prime representative of androgens is testosterone. Long-lasting impact of androgens on susceptible hair follicles brings about their gradual miniaturization and leads to Androgenetic Alopecia, the most common type of hair loss in men.
ANAGEN PHASE: Approximately 80% of our hair is in the Anagen Phase, which lasts from 2 to 6 years. Hair follicles in the Anagen Phase are intensely active and hair grows daily circa 0.035cm.
CATAGEN PHASE: Catagen Phase is a transitional phase which prepares hair to come into the Telogen Phase and lasts 2 weeks on average. Hair follicles start shrinking, hair growth stops and hairs are being prepared to fall out. Approximately 1 to 2% of hair lie in the Catagen Phase.
DHT (DIHYDROTESTOSTERONE): Derivative of testosterone. Testosterone, with the help of the enzyme 5-a reductase is converted into DHT, which due to its presence on susceptible hair follicles is responsible for hair miniaturization (gradual shrinking of hair follicles that leads to gradual shrinking of hair). Hair loss is the final stage of hair miniaturization.
DONOR AREA: The area at the back and sides of the scalp is called Donor Area, as its hair follicles are extracted and transferred by the doctors in hair transplantation. Transplanted hair follicles preserve their genetic resistance to androgens even in the thinning area and continue to grow normally throughout a life time.
DONOR DOMINANCE: This principle has been the basis for the foundation and development of modern hair transplantation. It states that hair follicles from the donor area preserve their genetic resistance to androgens and continue to grow throughout a lifetime.
ESHRS: The acronym for the European Society of Hair Restoration Surgery, the European non-profit voluntary organization of surgeon specialists for the advance of hair restoration surgery.
FEMALE PATTERN BALDNESS: This type of hair loss is clinically described by the Ludwig Classification. Women are usually affected by diffuse hair loss with emphasis on the upper area of the scalp, while at the same time preserve the frontal line.
FOLLICULAR UNIT HAIR TRANSPLANTATION: Is the transferring of hair follicles from areas of the scalp with hair adequacy to areas with hair deficiency. The extraction of hair follicles and their reimplantation to the area of hair loss has no impact on their function and they continue to grow normally throughout a life time.
FUE (Follicular Unit Extraction): It is the hair transplantation technique in which hair follicles are extracted one by one from the donor area.
FUT (Follicular Unit Transplantation): It is the hair transplantation technique in which hair follicles are received through microscopic dissection of a single strip of hair removed from the donor area.
HAIR CLONING: Hair follicle cloning is the experimental technique described from the following steps:
• Extraction of cells from hair follicles
• Multiplication of extracted cells in vitro
• Reimplantation of the new cells on the scalp in order to produce new hair follicles
HAIR FOLLICLES: Hair grows in naturally occurring group of 1-4 hairs, called Hair Follicles or Follicular Units. Hair follicles are complete biological structures that comprise nerves, blood vessels, sebaceous glands and the small arrector pili: this muscle lies at the base of hair follicle and in any excitement due to cold or fear, forces shaft to rise. Hair follicles are surrounded by protective, connective collagen tissue and lie everywhere in the body except lips, palms and soles. All hair follicles have a predefined genetic definition. Those consisting of one hair are allocated along the frontal hairline and as we move towards the back of the scalp, hair follicles constitute groups of 2, 3 or 4 hairs.
HAIR FOLLICLES REGENERATION: Researchers made trials on wounded mice: they took skin tissue of wounded mice and by using wnt protein they observed that cells of the epidermis present the properties of stem cells and regenerate hair follicles. New hair follicles can produce hair shafts which grow normally through all stages of the hair growth cycle. This outcome has created many hopes for hair loss treatment in man, as researchers have decoded the genes involved in the production of new hair.
ISHRS: The acronym for the International Society of Hair Restoration Surgery, the non-profit voluntary organization of surgeon specialists for the advance of hair restoration surgery.
KERATIN: Keratin is a group of proteins that contain sulphur and is being produced in the keratogen zone of the root. It contributes to the strength and resilience of the hair shaft and to nail configuration as well. Hair consists of proteins (65% – 95%), lipids (1% – 9%), trace elements, polysaccharides and water. Keratin also lies in the skin.
LUDWIG SCALE: The graphic representation of Female Pattern Baldness degrees.
MEGA SESSIONS: Hair transplant sessions of more than 2.500 follicular units.
NORWOOD SCALE: The graphic representation of Androgenetic Alopecia degrees.
RECIPIENT AREA: The thinning area of the scalp in which extracted hair follicles are reimplanted during hair transplantation.
SEASONAL HAIR LOSS: A type of reversible hair loss that is mainly noticed in spring and autumn. Occurs due to the seasonal impacts on hair follicles activity. It lasts approximately 2 months and in case that hair loss persists, further diagnosis should take place.
TELOGEN EFFLUVIUM: Telogen Effluvium is a form of alopecia characterized by diffuse hair shedding. There are 3 types of Telogen Effluvium: acute, sub acute and chronic. The interruption of the normal hair growth cycle can occur as a result of metabolic stress (chemotherapy, pregnancy, puberty, surgery, severe stress and chronic illnesses), emotional trauma or systematic attack. Hair loss appears 3 months after the experience of the intense incident and it may involve even 50% of hair in rare cases.
TELOGEN PHASE: The third stage of Hair Growth Cycle. It lasts approximately 100 days (3-4 months) and concerns 20% of hair. Hair follicles become inactive and hair is finally shed.
TRACTION ALOPECIA: Traction Alopecia is caused by the repeated pulling of hair and usually affects women who fix their hair tightly for a long period. The repeated traction can cause irreversible damage, due to the inflammation of hair follicles. Then hair does not regrow. In this case, hair transplantation can be a good solution.
TRICHOTILLOMANIA: Trichotillomania is a form of self-enforced scarring alopecia, in which the affected person develops the need to pull and uproot his own hair, usually by rolling his hair around his finger.