Alopecia is a disease of hair and scalp characterized by diffuse or fall located hair. Diffuse alopecia defined in relation to the normal fall of about 50 hairs a day. Some falls are of physiological hair (hair loss in the newborn and called seboreica the male sex).

Androgenic alopecia is very common in men, responsible for baldness common with dominant-hereditary predisposition. It begins after adolescence, particularly in the temporal region and is dependent on the affective attitude of the subject vis-a-vis the ornament to capillary. This type of baldness a woman must go in search of a virilization syndrome. Treatment of this type of alopecia disappointing and represents an important source of profit for dealing with medical products and para-medical.

Alopecia diffuse stress is due to timing of many hairs in phase telogena after febrile episode, a difficult Naser, a surgery or an episode negative psycho-emotional. Complete restoration by such an episode is made up in 4 to 6 months.

Toxic alopecia is due in particular anti cancer chemotherapy, anti tiroidienelor Synthesis, anti coagulantelor, anti convulsive or derivatives of vitamin A.

Diffuse alopecia  interest is observed in case mixedemului, insufficient pituitare, hipertiroidiei, hipoparatiroidiei, severe diabetes, colagenozelor, food gaps, malabsorption syndromes, syphilis.

Pelade disease is a frequent cause of still does, associated with vitiligo, with auto-antibodies stomach, anti-thyroid, heredity, diabetes, atop, mental trauma. Limit the net is without hair, the skin is shiny, the holes folliculitis pilo-sebum surrounded by broken wires in 1 cm, deformed shape of the exclamation sign.  Evolution is to increase spontaneous or whimsical for generalization.

Other alopecias are either traumatic: tricotylomania or alopecia created by different types of hair.

Alopecia cicatriciale follow any process that destroys pilose folliculitis: trauma, burn, congenital diseases, lupus, folliculitis, data modifications radiotherapy treatments, primitive epithelial cancers, metastases, etc..