Hair Loss

Androgenic alopecia (AGA): male androgenic alopecia (AGH) and female (AGF) also called androgenetic alopecia or hair loss common. This hair loss appears with age and results in baldness gulfs and top of the head in man (male androgenic alopecia), while in women, there was an overall decrease of the hair (female androgenetic alopecia) predominantly on top of the skull. Nevertheless, the appearance of hair loss occurs sometimes diffuse in male androgenetic alopecia and female alopecia also leads sometimes slightly depleted gulfs. Scarring alopecia: Hair loss is ultimately the result of a birth defect (congenital aplasia, Angioma), trauma (wounds, burns or operation), a disease of the scalp (lupus erythematosus, lichen planus) or tumor of the scalp (basal cell carcinoma, squamous cell carcinoma), whose evolution has resulted in the formation of a close to that of abnormal scar tissue.

Diffuse alopecia: overall decrease in density of the hair.

Localized alopecia: localized decrease in capillary density.

Anagen: the anagen or growth phase of the hair affects 80 to 90% of hair and lasts 2 to 6 years (3 years or 1000 days in humans, five years in women This phase determines the final length of hair that. grows about 0.4 mm per day (1 cm per month).

Catagen: the catagen phase is a resting phase of the hair that lasts three weeks and covers about 0-2% of the hair. During the hair cycle, this phase is intermediate between the anagen growth phase and the telogen phase of involution.

Fall normal hair: hair fall and are constantly renewed. The normal drop is 45 to 60 hairs per day, it is up to the end of the summer and spring.

Scalp, the skin covering the skull and contains the hair follicles.

Hair cycle: human hair evolves in stages grouped under the term of the hair cycle. We distinguish anagen growth phase for 80 to 90% of hair and lasts 2-6 years. The catagen phase or hair growth stops, it takes about 2-3 weeks for 0-2% of the hair. The telogen phase or involution hair fall, it concerns 10-20% of the hair and lasts about two to three months. the cycle is then repeated. All hair loss include alteration of the hair cycle.

Congenital: Present at birth. Hair dysplasia: abnormal hair structure.

Anagen effluvium: indicates hair loss important. Hair fall during its growth phase. This variety of hair loss is the most rare and most often occurs after taking medications such as chemotherapy that interfere with the production of hair or in alopecia areata.

Telogen effluvium: indicates hair loss and significant transient. The hair growth phase or phase involution rushed fall (exogenous phase) or the hair growth phase are precipitated in involution phase and then fall. The telogen effluvium occurs a few weeks after childbirth, surgery, high fever or taking certain medications, but may also be in a rush of androgenic alopecia.

Exogenous: the exogenous phase is a special time of the telogen phase where the hair fall. Approximately 1% of hair in the telogen phase are lost every day.