Table of Contents
- 1 Life cycle of hair
- 2 Unsynchronized growth
- 3 Variable life cycle
- 4 Hair Structure
- 5 Hair loss
- 6 Types of hair loss
- 7 Treatment of hair loss
- 8 References
Life cycle of hair
Our hair, composed of 120,000 to 150,000 hairs, is naturally renewed throughout the life. Every hair grows, dies, falls and regrows, following a steady cycle of about 3 years for men and 4 to 7 years for women.
Throughout our lives, our hair regenerates many times, but over the years, hair follicles change under the influence of various factors: age, hormonal changes, oxidative stress, nutrition, pollution, etc. Then, the follicles begin to produce thinner and thinner hairs until their activity stops entirely, leading to thinning of the hair.
Hair growth is not a continuous process but develops following three consecutive phases:
An anagen phase lasting from 3 to 7 years (depending on sex) at a time when the hair grows regularly about 0.3 mm. per day (or about 1 cm per month). While in the anagen phase, the root is deep in the dermis. It is bulging and fulfills the hair follicle. New keratinocytes are produced at the matrix level and they push the old ones outwards, thus prolonging the hair.
A catagen phase lasts for 3 to 4 weeks. During this phase, the keratinocytes of the hair bulb degenerate and the hair stops growing. The bulb loses its volume and climbs slowly to the surface of the scalp, interrupting the connection with the dermal papilla: this causes the hair destruction.
A telogen phase lasting from 3 to 4 months: the hair falls naturally under the influence of friction, brushing and the pressure of the new root that forms in the scalp. Then comes a latent period in which nothing happens before the start of a new cycle.
Despite these phases, through which all of our hair passes, our hair retains a constant apparent density (beyond pathological cases). This is explained by the fact that the cycle of each hair is independent of that of the others, ie. Not all hair falls at the same time.
At any given time, about 90% of our hairs are in an anagen phase: Thus, the small amount of about a hundred hairs that we lose every day remains unnoticed.
Variable life cycle
The life cycle of the hair is different in individuals because it is influenced by a number of factors:
In infancy, the hair percentage in the anagen phase is at its maximum. Later, during the period of puberty, it is slightly lower.
Asians, Afro-Americans, and Caucasians do not have the same life cycles of their hairs. For example, in people of Asian origin, the anagen phase is quite long.
The anagen phase lasts longer for women than for men: this explains why their hair is usually longer.
Male hormones (androgens)
They have a strong influence on the hair cycle, and can accelerate it dramatically. This way the hair follicle reaches the end of its production capacity way faster and the hair dies permanently.
The hair in the telogen phase is thicker in the spring and autumn. Therefore, it is normal for your hair to fall over these periods.
The lack of some ingredients may shorten or even stop the growth phases of the hairs. Proteins, vitamins, minerals and essential fatty acids are essential for good hair health.
Composed of about 95% keratin, the hair has a complex layered structure. The visible part of it, whose glamor and flexibility we admire, is biologically dead – the living part of the hair is its root deep inside the scalp.
Just like the nails and the hairs on the body, the hairs on the head consist mainly of keratin , a solid and a fibrous protein substance. Typically, hair consists of 120,000 to 150,000 hairs, or about 250 hairs per cm2 of the scalp, with an average diameter of 50 to 100 micrometers.
The hair consists of two parts: root and shaft.
Root or hair bulb
The living part of the hair is located in the hair follicle at about 4 mm. under the scalp. It contains several zones, each of which has an important role in hair life:
- Dermal Papilla: vascularized with a blood network, it carries all the nutrients it necessary for the hair growth. It is also the “brain” of the hair: it manages the production of the various capillary cells.
- Matrix: this is where keratinocytes, the basic hair cells, multiply and fill with keratin. The matrix also harbors the melanocytes that produce hair coloring pigments (melanin).
- Epithelial envelope: divided into two layers (internal and external epithelial envelope), it serves to maintain the stem of the hair during its formation, as it is still soft and vulnerable during this stage.
- Sebaceous glands: located under the skin (near the scalp) and attached to the hair follicle, they secrete sebum. This substance, which is necessary for the good health of hair, protects, nourishes and provides it with flexibility and shiny appearance.
This is the visible part of the hair, the shaft is biologically dead: in fact, it consists of dead cells filled with keratin. It is structured in three concentric layers:
- Medulla – a soft substance found in the shaft, consisting of clustered cells without a nucleus.
- The cortex, which coats the medulla and represents 80 to 90% of the weight of the hair. It consists of two types of keratin fibers (horizontal and vertical) that give the hair flexibility and strength. The cortex also contains the melanin pigments, which give the color of the hair.
- The cuticle is the outermost layer of hair formed by colorless keratin flakes placed on top of each other and connected to intracellular substance rich in lipids. Although very fine, the cuticle’s role is to protect the cortex: it is the one that faces all the daily aggressive factors (water, dirt, sun, wind, etc.). The texture and the shine of the hair depend directly on the cuticle influence, so it is of utmost importance to take care of it.
Hair loss  (which can be provoked by stress and anxiety) is more common in men, but it also affects some women. It can manifest itself in various forms and be caused by many factors. Timely care is the key to the effective treatment.
The hair is constantly renewed and it’s absolutely normal to fall down every day (especially during spring or autumn). As people grow older, it is just as natural to see the hair lighten: gradually new hair becomes thinner than the previous ones.
Hair loss becomes a problem when we lose more than a hundred hairs a day. In a long term, it can result in thinning or falling of the hair, which is sometimes difficult to accept (it can be considered as an aesthetic problem).
Types of hair loss
The most common cause of hair loss is androgenic alopecia , i.e. whose origin is both hormonal and genetic. It is much more common in men – one in two men aged 50 years is affected, and sometimes the condition can even start in puberty. In women, the hair starts thinning on top of the scalp.
Androgenic alopecia is due to increased sensitivity of hair follicles to the androgenic hormones. These male hormones lead to accelerating the hair’s life cycle, which gradually exhausts the hair follicles. They end up stopping their activity and the process leads to hair thinning.
Alopecia areata on a healthy scalp
In this case, hair is thinning or missing in certain areas of the scalp, while the rest of the hair is normal and the scalp is healthy. Alopecia areata  ( an autoimmune disease leading to complete hair loss in small areas of the scalp) and trichotillomania (nerve tics consisting of hair tightening or wrapping) are the two main causes of this type of alopecia.
Some excessively tight hairstyles (coat, horsetail, braids) can also cause hair loss. This phenomenon is more common in curly hair.
Alopecia areata on a damaged scalp
Some diseases or skin infections (lichen planus, lupus, etc.), as well as scarring or burns, can cause the destruction of the hair follicles in certain areas. These areas are often completely hairless. It is important to quickly distinguish the origin of hair loss: inflammatory diseases (lichen planus and lupus) can lead to irreversible hair loss if diagnosed too late.
Scabies, a fungal scalp infection, also generates alopecia areata. This condition is particularly common in children. After the healing period, the hair is recovered in the majority of cases.
Sudden, abundant and scattered hair loss, telogenic effluvium  may be due to physiological (lack of nutrients due to birth or surgery, excessive fatigue, etc.) or psychological (emotional shock, intense stress, depression) factors.
Usually harmless, in most cases, it is self-resorbable within a few months.
Treatment of hair loss
It is crucial to start treatment as early as possible in order to avoid long-term or even permanent baldness: in fact, treatments are more effective when hair is not dramatically affected. Consult your dermatologist as soon as you determine the initial stage of hair thinning.
The specialist will determine the nature of your hair loss and its causes so that he or she can arrange appropriate treatment: local care, oral medication, or surgical intervention( in the most serious cases).
The natural shine and the flexibility of your hair depending on its condition and on your overall health, but also on your diet and the care you provide on daily basis: washing, drying, brushing …
Here you can discover some practical advices – what’s good doing daily for shiny and healthy hair!
- From a hygiene perspective, shampooing is enough every 2 to 4 days. Whether you choose to wash your hair every day is a matter of personal convenience. It is good, however, to know that too frequent washing with shampoo can make your hair grease faster.
- Choose a soft shampoo suitable for the type of your hair. Apply a small amount to form mild foam. While shampooing your hair, gently massage your scalp with your fingertips: such massage allows you to activate blood circulation and thus improve the contribution of essential nutrients to the root of your hair. Finally, rinse very carefully: If you let product hang out until your next wash—and pile on styling products and dry shampoo all the while—it’ll turn into buildup, which can irritate the scalp and even slow growth by clogging up the hair follicles.
- It is not necessary to rinse with very cold water: the myth that cold water allows the hair to be brighter has no scientific justification.
- Once a week, apply a nourishing product after the shampoo. The oils that are applied and left to work after the shampoo allow the hair to be deeply nourished.
- If your hair is thin, dry or brittle, wait until it dries out completely before you start brushing it: it’s more fragile when wet. Try to brush small sections of hair from the ends toward the scalp starting from the tips and climbing gradually to the root.
- After washing, you want to get rid of the moisture as quickly as possible, so make sure you’re efficiently towel-drying. This means tossing your cotton towels and relying instead on microfiber fabric, which absorbs moisture exponentially better and is gentler on your hair cuticle.
- If you use a hairdryer, it is extremely important to use the cool air to the hot, which is aggressive for the capillary fiber, and do not put the hair dryer too close to your hair.
- Avoid the hair straightener, it is very aggressive for the hair fibers, or use it only exceptionally.
- Use hair dye no more than once a month, and try to use ammonia-free formulas, as they are less corrosive.
- In the morning and in the evening, carefully brush your hair with a natural hair brush that is more gentle for the capillary fibers. Hair brushing in the evening helps to free the hair from the dust and dirt accumulated during the day.
- Maintain a varied and balanced diet. Pay special attention to the intake of proteins, iron, zinc, magnesium and vitamins, the main nutrients for hair health.
- Several times a year, feed your hair with hair supplements
The desire to fight baldness has always been great. Many methods have been described to restore hair density – from scientifically proven, slightly ineffective to frankly speculative.
There are various recipes based on plants, which are thought to stimulate hair growth and have more than two-thousand-year history. For some people, such mixtures actually provide with great results but, unfortunately, not every time.
Hair transplantation , however, promises great results and therefore can be considered the most effective method for the time being.
Remember that balding is a normal manifestation of the overall aging process. Both women and men notice that as their age progresses, their hair decreases and its loss leads to a great emotional discomfort. The problem can be successfully solved by the procedure of hair transplantation.
Before the hair transplant procedure
Baldness usually begins in the vertex or forehead area. In these areas, hairy bulbs have receptors, which are very sensitive to testosterone, which makes hairs vulnerable. The preserved bulbs remain in the area above the ears and around the neck in the occipital area of the scalp where there are no such receptors.
Today, one of the most common ways to anatomically correct baldness on a surgical path is hair transplantation. The method allows correction in cases of varying degrees of hair thinning. Its advantage is that the maximum natural result is achieved and that the newly applied hair continues to grow.
The hair transplant procedure is a surgical method by which hair follicles are redistributed from areas free of baldness to those in which the process is active. The operation takes place in two stages: material (hair follicles) for transplantation and implantation. There are different techniques for hair transplants, each of which has its own pros and cons.
One of the most common methods of taking material before the hair transplant operation is through a donor tape (strip). Another technique is the single grafting by micro-zinc, and here are two variants. One is manual, the other is automated. The automated method uses a special robot. Working with such robot, the hair transplantation significantly shortens the duration of the first stage, allowing for a larger number of quality microcapsules (up to 2500 in one stage) with less discomfort for the patient.
The implantation of the material is carried out with special injectors of the diameter corresponding to the diameter of the micrographs. There are other methods of implantation, which are of historical importance to us.
The realistic idea of the entire hair transplantation procedure and its long-term effect is of great importance in conducting the consultation. Discussing the treatment methods and taking into account the color of the skin and the hair of the patient are very important steps. In order to achieve satisfactory results in fine straight hair, which contrasts in color with the scalp, a higher grafting density is required. Coarse, brittle hair may require a lower density. A digital microcamera (trioscopy) study is conducted to provide information on the number and structure of injured hair and the status of the scalp.
Testing with does not require the removal of a large number of hairs (50-60), and provides information on the density of the hair in the unaffected areas and a number of grafts needed to restore the hair in the affected areas. The family history of hair loss of both parents is also important. The hair transplant operation is only recommended if there is a good chance of achieving the desired result.
After the hair transplant procedure
Hair transplantation provides with visible results within 4-6 months after surgery and depends on the hair’s life cycle. After the hair transplantation, the new hairs often fall within the second month, after which an active growth of new hair is observed.
The procedure for hair transplantation is an extremely gratifying option for the patient, but only if it is planned very carefully by the surgeons performing the transplantation.
Structure and functions of keratin proteins in simple, stratified, keratinized and cornified epithelia
Hair transplantation surgery