Normal Alopecia
This is the normal hair loss that comes as a result of our hair renewal process.
Alopecia areata also includes seasonal hair loss.
Alopecia areata
It is a rare (at a rate of 1%) autoimmune type of hair loss in which the immune system through T-lymphocytes attacks the hair follicles forcing them to enter the telogen phase.
The full causes of the condition have not been elucidated. It appears, however, to be related to genetic, psychological and immunological factors.
The disease refers mainly to young people (5 to 30 years old) and its evolution varies from patient to patient. It is characterized by areas of complete denudation in a normal skin area.
Alopecia areata does not only refer to the hair as it is possible to affect the beard, eyebrows, eyelashes, armpit or pubic hair.
Androgenetic alopecia or male-pattern baldness
It is the most common form of hair loss in men also known as male pattern baldness.
The condition is a result of the chronic degenerative action of androgens in people who show sensitivity to the above action.
There is a clear relationship between the above sensitivity and heredity.
The progression of androgenetic alopecia is progressive starting from the front and top of the scalp, extending to the sides and back, eventually leaving only the last two areas unaffected, and involves both thinning and hair loss.
The rate of progression can vary greatly from person to person.
Diffuse Alopecia
Diffuse alopecias are defined as alopecias in which the thinning is observed over the entire length of the scalp.
Diffuse alopecias do not refer to a specific disease whose form and progression can vary from patient to patient.
On the contrary, we can talk about a group of forms of hair loss with a common characteristic of the diffusion of thinning throughout the scalp area, which occurs for a different reason, in a different way and process.
Thus, in terms of the way of manifestation, diffuse alopecias are distinguished into:
A. Acute, in which there is sudden hair loss
B. Subacute, in which the dilution process takes several months
C. Years, in which the process of dilution is repeated in cycles
According to the point of the hair growth cycle that is affected, diffuse alopecia are divided into:
A. Telogen Effluvium
Abrupt transition of hair to the telogen phase. Diseases, hormonal changes, stress, lack of certain nutrients, etc. may be the causes of such hair loss.
B. Anagen or Dystrophic (Anagen Effluvium)
Inhibition of hair follicle function in the anagen stage due to an extremely damaging factor such as chemotherapy or radiation.
Hair loss may or may not be reversible depending on whether the hair follicle has died.
C. Mixed
Some hair follicles enter the telogenesis stage abruptly, while in others the regeneration function is inhibited.
Depending on the nature of the cause that creates widespread hair loss we can distinguish:
A. Endocrine disorders, such as diabetes mellitus, thyroid disorders, or pregnancy.
B. Medicines and Chemical substances, such as insecticides, anticoagulants, antipsychotics, etc.
C. Nutritional and metabolic disorders, such as iron, protein or zinc deficiency.
Traumatic alopecia
It can be caused by trauma (eg, a burn), by stretching or pulling the hair, or by twisting the hair around the finger as in the case of trichotillomania.