Generality
Within certain limits, hair loss is an absolutely physiological event. Broadly speaking, the loss of 40 to 120 hairs per day is considered normal, based on the number of hair follicles still active and their growth cycle.
In fact, the number of hairs that fall in a day can vary greatly from individual to individual, depending on a number of factors, such as:
- Sex (generally, men lose more hair than a woman during the day);
- Amount of hair - therefore of bulbs - present in the scalp;
- General state of health of the patient (as explained in the next paragraph, in fact, some diseases can promote hair loss);
- Nutritional deficiencies;
- Types of hair care products used (the use of overly aggressive products, in fact, in addition to damaging the scalp could also promote hair loss).
Causes
What are the causes and predisposing factors for hair loss?
Despite hair loss - within certain limits - it is considered a normal phenomenon, there are conditions in which hair falls out conspicuously. This is the case of menopause, for example, but also of pregnancy, stress, drastic diets, alcohol abuse, taking some drugs, undergoing surgery, the spring period and in particular the autumn period .
Excessive hair loss can also accompany various pathological conditions (thyroid diseases, sunburns, iron deficiency anemia, malnutrition, physical trauma, cachexia, high fever and psychophysical stress).
All these conditions occur clinically with an increase in daily hair loss.
The main cause of baldness remains however androgenetic alopecia, although in general it is a very slow and progressive process.
Telogen effluvium
Unlike animal ones, human follicles in good health have independent life cycles, with phases of growth and rest that are out of phase with those of adjacent bulbs; for this reason we do not realize the continuous renewal process of our hair. When some of the conditions listed above take place, and in general a violent psycho-physical stress, the hair follicles are induced to pass in mass from the phase of anagen (growth) to that of catagen (involution), with prolongation of the period of rest and fall (telogen). Thus a hair loss occurs, numerically very high and qualitatively homogeneous, defined as " telogen effluvium " or "effluvio".
The consequences can be particularly alarming ... dozens and dozens of hairs that accumulate on the pillow or remain in the hands and in the towel with which they are dried. Unlike androgenetic alopecia, in the telogen effluvium, hair loss extensively affects the entire scalp, including the lateral and posterior parts of the head. Fortunately, in most cases where unfavorable genetic predispositions are lacking, there is a subsequent and almost complete regrowth.
Of the 100 hairs normally lost every day - on the more than 100, 000 on average in the scalp - about 10% is in the telogen phase (rest); when the effluvium occurs, this percentage rises to 30%.
There are two types of telogen effluvium: the acute type and the chronic type.
The acute telogen effluvium is characterized by a sudden and conspicuous loss of hair and finds its main cause in particularly intense situations of stress, but of short duration (as can occur, for example, in case of accidents or loss). These conditions, in fact, would cause a halt in the cell division that leads the hair from an anagen growth phase to the telogen phase. This type of effluvium generally lasts two or three months and, as a rule, resolves spontaneously.
Chronic telogen effluvium, on the other hand, can be triggered by causes of different origin and nature, such as, for example, anxiety disorders, nutritional deficiencies, drug intake, the presence of particular types of pathologies, endocrine disorders, etc. This form of effluvium can last for months and sometimes for years and does not resolve spontaneously as it happens, instead, with the acute form. Therefore, with the passage of time, the patient will find himself with an ever lower amount of hair that will tend to decrease further with the passage of time.
Anagen effluvium
On the other hand, there is also an anagen effluvium, in which the particularly marked fall involves hair that is still growing. The phenomenon occurs within a few days of the triggering cause, while in the fall from telogen effluvium the causal factor may precede hair loss even by a few months.
Treatment
When the amount of hair fallen daily becomes excessive, then it is advisable to worry and a consultation with a doctor specialized in this field (the trichologist) is necessary.
First of all, the doctor will determine the cause of the major hair loss in order to proceed with the most appropriate treatment for each case.
In the case of acute telogen effluvium, the most effective treatment consists in removing the cause that caused it; therefore, it is necessary to act on the stress that gave rise to the whole and wait for the effluvium to resolve spontaneously.
In the case of chronic telogen effluvium, however, the trichologist may decide to use topical corticosteroid drugs.
If hair loss is caused by other causes (androgenetic alopecia, alopecia areata, etc.), it will be the doctor's responsibility to diagnose and prescribe appropriate therapy to the patient (for more information: Androgenetic alopecia - Alopecia areata - Female Androgenetic Alopecia).
