Hair loss refers to physiological processes and is the result of the growth and renewal of skin cells and its appendages.. If more than 80-100 hairs are lost daily, then this is already a pathology.. In addition to hereditary factors, dietary habits, environmental conditions, hormones affect hair loss in women on the head, and which ones and how, let's take a closer look.

In women, hair loss on the head may be responsible for a number of hormonal disordersHormones and hairSkin and hair are target organs for many biologically active substances. The imbalance of hormones is reflected in the hair follicle, which is sensitive to changing conditions of hormonal regulation.. The processes of growth and hair loss are influenced by female and male sex steroids, hormones of the adrenal glands, thyroid and parathyroid glands, prolactin, somatotropin and melatonin.

AndrogensMale sex hormones - androgens, are produced not only in the body of men, in women they are produced by the ovaries and adrenal cortex. An increased amount of the main androgen - testosterone, is the most common cause of pathological hair loss in women, called alopecia, or baldness.. There are several types of alopecia:.

androgenic or androgenetic;

diffuse or symptomatic;

focal or nested;

cicatricial.

The most common - androgenetic, proceeding according to the so-called male type, leads in women to thinning of the hairline in the area of \u200b\u200b\\u200b\\u200bthe central parting and side surfaces of the head.

Male steroids realize their effects through a number of mechanisms..

Scope of application.

Mechanism of action.

Hair papilla (an area of \u200b\u200bskin with blood vessels and nerves that feeds the hair root).

Androgens bind to special receptors in papilla cells and block the production of factors responsible for the division of hair follicle stem cells.. This prevents the hair from reproducing at its former intensity or makes it impossible to grow..

Skin around hair follicles.

With androgenetic alopecia, the scalp becomes thinner, its blood supply and tissue oxygenation deteriorate, and as a result, the follicles are located superficially: the immersion depth is about 1 mm. Normally, in women, the depth of the hair follicle in the scalp is approximately 3 mm..

Orifices of hair follicles.

At first, some hairs still remain, but become thinner and discolored - the scalp shines through them. After several years, the mouths of the follicles become overgrown with connective tissue, and even such hairs stop growing..

The sensitivity of receptors to androgens, and hence the likelihood of developing androgenetic alopecia, largely depends on heredity.. It has been proven that the predisposition to hair loss in 70-75% of cases is transmitted from the mother and only 20% from the father.. The remaining 5-10% is due to baldness in individuals who have become the first in the family..

Estrogens A close relationship and common metabolism with male sex steroids are estrogens, or female sex hormones.. But only the effects that they have on the condition of the hair are diametrically opposed to the influence of androgens..

Estrogens modulate the hair growth cycle, which is represented by several consecutive periods.

Period name.

Period duration.

Hair processes.

Anagen - a period of growth.

2–4 years.

Active growth. The growth rate depends on the time of year: in winter there is a more intensive growth of the scalp.

Catagen - Interim.

2–3 weeks.

Growth is stopped, pigment is not formed, but the functionality of the hair papilla is preserved. The papilla itself gradually moves to the surface of the skin.

Telogen - dormant period.

3–4 months.

Growth is completely halted. The hair falls out on its own or is easily removed when a new one begins to grow under it from the remaining papilla.

Estradiol, which is the main and most active representative of estrogens, prolongs the first period of the life cycle - the growth phase. This is confirmed by the pattern observed in pregnant women.. During gestation, the level of estrogen in the woman's body increases, which leads to an increase in the number of actively growing hair and their total number on the head..

After delivery, the estrogen content decreases, and the hair that has been in the growth period longer than usual begins to leave the head synchronously.. The hairline is thinning, but only for a while. Normalization of hormonal balance returns the hair to its former appearance.

After the onset of menopause, when the amount of estrogen also decreases, similar changes occur..

The density of the hair decreases, but in this case the process is not temporary, since the functional activity of the ovaries stops completely.

In addition to a direct stimulating effect on the hair follicle, estrogens further reduce the negative effects of androgens.. This becomes possible due to the ability of estrogens to inhibit the activity of the reductase enzyme that converts testosterone into its biologically more active form - dihydrotestosterone..

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