Hair loss, alopecia
Hair life and natural hair growth cycle
As all cells of our body, our hairs are alive and are following a natural growth cycle: hair growth cycle. Hair growth cycle occurs in three phases: anagen, catagen and telogen.
Anagen phase
The anagen phase is the active growth phase of hair. It is the longest phase of the hair growth cycle and it may vary from 2 to 5 years. The vast majority of hairs on our head are in the anagen phase.
Catagen phase
The catagen phase is known as an intermediate phase for our hair. The growth of the hair stops completely when the hair is in the catagen phase. This stage lasts for about 3 weeks, which is really short compared to the first phase.
Telogen phase
During the telogen phase, hair does not grow, but remains attached to the hair follicle. At the end of this phase the old hair falls and leaves place to a new follicle in the anagen phase. Growth cycle starts all over again. It is important to note that while the amount of hair in telogen phase remains limited, there is no need to worry when the hair loss is around 50 to 100 hairs a day.
The number of hair cycle is limited: all life long we can count up to 25 to 30 cycles during our entire life. These cycles have a duration of two to five years; we have in theory enough hair cycles to keep your hair throughout our lives.
Unfortunately, for various reasons, the duration of these cycles can significantly decrease and lead to total collapse of capillary potential in just a few years. The hair then becomes finer and the final result is baldness.
Alopecia
What is alopecia?
Alopecia is hair loss on all or part of the scalp. We naturally lose an average of 60 hairs per day. There are some seasonal variations, with a higher loss in the spring and fall. However, a loss of more than 100 hairs per day is always excessive and could be alopecia. Especially if it persists, it is abnormal and it should be treated.
Alopecia affects approximately 20% of men of 20 years old and then increases by about 10% every 10 years. For men, hair loss results in baldness of gulfs and of the top of the skull. Often, alopecia is progressive and predictable. After 50 years of age, more than 50% of men have some degree of baldness (alopecia).
If baldness is mostly a male phenomenon, alopecia also affects women. We observe an overall decrease of women hair, particularly on the top of the skull.
Do not wait! Early treatment has a better chance of success agains alopecia.
Androgenetic hair loss
This type of hair loss is called "androgenic" because there is a hereditary predisposition. Thus, most individuals affected by hair loss have a father or a grandfather who faced this problem before; but it does not mean that an individual suffering from androgenetic hair loss will have a child predisposed to hair loss.
Schema of Androgenetic hair loss
Many scientists’ researches have established the key role of an enzyme called "5-alpha reductase" in the androgenetic hair loss. This hair loss is due to a hyper activity of an enzyme that transforms testosterone (male hormone) to dihydrotestosterone (DHT) and thus contributes to shortening the growth phase and to the miniaturization of hair in the growth phase.
Schema of androgenetic hair loss
Diffuse hair loss
Diffuse hair loss is most frequently encountered by women. It affects about 30% of women in their life. It is characterized by fine and thinning hair throughout the scalp. This hair loss is not hereditary and can occur at any time of life, it is often due to external factors such as:
- stress;
- exhaustion;
- overwork;
- medication;
- poor nutrition;
- childbirth;
- pollution ...
Schema of diffuse hair loss
However, it seems established that the release of free radicals maintains tissue inflammation and induces aging of hair follicle. This inflammation can be recognized as a cause of the shortening of the hair life.