Understanding your hair is the first step towards looking after it
Hair
Your hair is an essential part of you. In addition to expressing your image and identity, it has a key biological function: it protects you from external agents, helps maintain your body temperature and mirrors your state of health.
Each strand of hair is born inside the hair follicle, a living structure that works in cycles to keep hair growing continuously. At the base of it is the hair bulb where cells multiply, keratinise and turn into the hair shaft as they are moved upwards. Growth depends on the activity of both these cells and the dermal papilla, which contains the blood vessels responsible for supplying the oxygen, nutrients and hormones which govern how, and how much, the hair grows. Around the hair follicle are the sebaceous glands responsible for producing sebum, which hydrates and protects the hair.
This is how your hair is born and grows: from the root to the hair fibre you see every day.
The hair's natural cycle
Hair growth is not constant: it is dictated by the hair follicle, which follows a natural cycle in which each strand of hair grows, rests and finally sheds so that a new strand can replace it. Because each follicle is at a different stage in the cycle, hair is constantly renewing itself and we do not lose all of it at the same time.
Did you know that the secret to strong, full hair lies in balance?
When your hair cycle is in balance, most of your hair is growing and only a small portion of it sheds naturally. The hair follicle is in optimum conditions for each hair to be born strong, complete its lifetime and then be replaced by a new one which is just as healthy and resilient.
When the balance is upset, your hairs sheds more than usual
We lose between 50 and 100 strands of hair every day. And this is good: it is a normal part of the hair cycle. But when something disturbs the cycle, it becomes imbalanced and shortens: the hair follicle is deprived of what it needs, the new hair is born weaker, and there are fewer hairs in the growth stage and more in the shedding phase.
Causes of hair
loss
Hair loss is the visible sign of internal and/or external imbalances. There is no single cause, but rather may be —and very often is— due to the combination of various factors that affect hair follicle operation and disturb the natural hair cycle. Some cause temporary hair loss; others chronic.
Androgens such as testosterone, and its most active derivative dihydrotestosterone (DHT), are the main regulators of hair growth.
In the hair follicle, the 5-alpha reductase enzyme converts testosterone into DHT. This transformation is a natural bodily process: DHT has stronger biological action and regulates functions such as sebum production and the activity of hair follicle cells.
The problem arises when DHT levels increase, or when follicles become more sensitive to its action. In these conditions, the hair cycle is upset: hair enters the shedding phase more quickly, the follicle shrinks and new hairs are born weaker and finer. This is one of the hormonal mechanisms most characteristic of chronic hair loss linked to genetic predisposition.
Other hormonal changes during life stages also have an effect on the hair. During pregnancy, oestrogens lengthen the growth phase and hair looks stronger; post-partum, the sudden drop in oestrogen and progesterone levels causes temporary hair loss; during the menopause, lower oestrogen and progesterone levels lessen their protective effect and the hair follicle is left more exposed to androgen activity.
The common denominator is the same in all cases: a hormonal imbalance that upsets the normal operation of the hair follicle manifests itself in a loss of hair thickness.
Genetics are one of the key factors in hair health. Various studies have shown that between 40 and 50% of women who lose hair density have a family history of this issue, particularly the early-onset variety.
Scientific research has shown that this predisposition does not depend on a single gene, but that rather results from polygenic inheritance involving various genes and manifesting itself with different intensity depending on the individual. It means that some follicles are more sensitive to androgen hormone activity, particularly dihydrotestosterone (DHT). As a consequence, the follicle becomes weaker, new hairs are born finer and the growth cycle becomes shorter.
To sum up, genetics are not the sole cause of hair loss, but they do determine the degree of sensitivity of hair follicles. For this reason, when there is a hereditary predisposition, hormonal imbalances have a higher impact on hair health and volume.
How we live —what we eat, the habits we have— can affect our hair.
The hair follicle is a highly active tissue that requires a constant supply of proteins, vitamins and minerals. Highly restrictive diets, rapid weight loss or nutritional deficiencies —such as lack of iron, zinc, essential amino acids or vitamin D— can weaken hair, shorten its growth phase and promote its shedding.
Sleeping less than we should or having broken nights are also linked to increased risk of, and more pronounced, hair loss. Clinical studies have shown that sleeping ≤ 6 hours a night increases the risk of severe hair loss some 2.16 times, and poor scores as regards sleep quality (PSQI) are also linked to more severe symptoms.
These daily habits can trigger or exacerbate hair loss, whilst a balanced diet and proper rest can help keep your hair healthy and strong.
Hair is also exposed to the effects of the environment. Environmental pollution and ultraviolet (UV) radiation are two of the most widely studied external factors, in view of their link to hair loss.
Both of them encourage the formation of free radicals, highly reactive molecules which, when they build up to excess, cause what is termed oxidative stress, a phenomenon that damages hair follicle cells and speeds up hair loss.
Our body has natural defences (antioxidants) to neutralise free radicals, but when the balance is upset, they outstrip our antioxidant capacity and the hair follicle is affected:
- Increased cell destruction.
- The hair lifecycle shortens (hairs exit the growth phase more quickly and enter the shedding stage).
- Hair becomes progressively finer, more fragile, and more brittle.
Our hair also reveals our emotional state.
Science has shown that women who have high stress levels are up to 11 times more likely to suffer hair loss than women who do not.
When we go through difficult periods —with anxiety, worries or prolonged stress— the body releases more cortisol, the stress hormone. If cortisol levels remain high, the normal operation of hair follicles is upset and the hair cycle too:
- Hair exits the growth phase (anagen) more quickly and enters the shedding phase (telogen).
- There is a drop in the production of proteoglycans, crucial molecules that protect hair and stimulate its growth.
- The hair root becomes progressively weaker.
With the passage of time, the hair growth phase (anagen) becomes shorter and the proportion of hairs in this phase also lessens. This means that new hairs are finer and weaker.
Getting older also exposes us to emotional and physical experiences that can promote hair loss. Hormonal changes associated with life stages such as the menopause, along with genetic predisposition, make this process more obvious over time.
Added to this are the health and lifestyle factors that become more common in adult life —such as chronic illnesses, nutritional deficiencies, stress or lack of rest— and that affect hair volume and quality.
Age therefore acts as a factor that accelerates the natural weakening of the hair follicle and contributes to hair progressively losing its strength and thickness.
Complidermol®
In balance with your hair
When you restore its strength, you recover your confidence and well-being.
