UNDERSTANDING HAIR LOSS
What is the life cycle of a hair? Where does alopecia come from?
Did you know that hair loss affects 10 million men and 2 million women in France? If 20% of 20-year-old men suffer from it, about 50% will experience baldness when they approach their fifties. But where exactly does this phenomenon come from? What is the natural life cycle of a hair? What are the factors that exacerbate alopecia? Here are some explanations on the subject.
The life cycle of hair: a repetitive scenario
Hair is constantly renewed like skin. The average life cycle is about 3 years in men and 4 to 6 years in women. When it dies, it is normally replaced with another hair, which causes it to fall out. Here are the different stages in a hair’s life:
- Anagen, ie hair growth: In this period, which lasts for a few years, hair grows continuously under the effect of keratin.
- Catagen or hair deterioration: At this moment, growth stops and the hair root splits to rise towards the surface of the epidermis. This stage takes about twenty days.
- Telogen or hair death: the hair is ready to fall out and the replaced bulb begins to grow at the bulb level. This process takes 2 to 6 months.
- Hair loss: When young hair growth reaches the scalp, ie the skin surface, it pushes the old hair and causes it to fall out.
- New anagen phase: new hair begins a growth phase in turn and the cycle repeats itself continuously.
When a person suffers from hair loss, this natural rhythm tends to accelerate. Gradually, the hair falls out faster, becomes more brittle and shorter. Eventually, the hairy capital runs out, leaving room for an empty space. This is the beginning of baldness.
What are the causes of alopecia?
There may be more than one cause of alopecia. However, heredity is the main culprit, especially in men like the hormonal factor. Among the most famous reasons:
When hair loss is hereditary, it is called androgenetic alopecia. In fact, like other parts of the body, hair inherits certain characteristics that have been identified from birth. Some people, due to their inheritance, stimulate the production of 5 alpha reductase, an enzyme that interferes with the dihydrotestosterone (DHT) hormone, to which hair follicles are very sensitive, faster and more intensely. This is what weakens the hair by disrupting the growth cycle.
When hormones are the cause of hair loss, it is called androgenic alopecia. In this case, a few hormones can affect hair, whether in men or women. It is testosterone in men. Hair loss in women usually occurs when female hormones fall suddenly. This phenomenon can occur after receiving a treatment, after childbirth, during menopause, or in a state of hormonal imbalance.
Stress is another trigger for alopecia. It tends to disrupt the adrenal glands, which eventually increases the production of male hormones. You should also be aware that the consequences of stress are not immediately visible. Severe shock can cause hair loss for up to 4 months after the event.
Alopecia areata is a highly mysterious disease that comes on suddenly and can affect men as well as women. It is characterized by the spontaneous appearance of glabrous patches of various sizes on the scalp. Although views on the origin of this disease differ, the emergence of stress plays an important role. Hair regrowth can be spontaneous and random.
Dietary deficiencies and especially iron deficiency cause hair loss. Indeed, when the body lacks iron, the blood is less oxygenated. However, this oxygenation is necessary for the health of the hair. Without it, hair becomes dull and more brittle.
Finally, taking certain treatments can cause hair loss. Alopecia can sometimes be a side effect of taking certain medications. This is especially true during chemotherapy.
Therefore, it is important to evaluate your health and lifestyle before you panic.