Hair Loss Reasons

What Are The Reasons For Hair Loss?

Hair loss can cause psychological and social problems for both men and women. Dr. Camacho and my fellow colleagues have observed an inclination to having depression in 55% of the women who have Female Pattern Hair Loss (FPHL). [1] On the other hand, in cases of Male Pattern Hair Loss, anxiety was observed in 78% of men and 22% of the men showing a more aggressive behavior. It is also observed that if the hair loss is treated, 89% of the women and 76% of the men showed improvement in these complaints.

So what are the reasons for hair loss which can make a person feel such distress? In actually there is no single unique answer to this question. Hair loss in men and women is multifaceted, which means that many factors are involved together.

Male Pattern Hair Loss

The major and most frequently observed reason for male pattern hair loss is the androgenic hormones. Currently the onset of hairloss in individuals is starting at ever earlier ages ( this may be due to enviornmental factors, diet, stress etc..). In order for the hair loss, which is normally starts in early puberty, to be noticed, a 50% loss has to be developed. For this reason, for people who are inclined to hair loss, it is very important to evaluate genetic screening tests, anagen/telogen ratios obtained by hair analyses and hereditary factors all together.

It is possible to slow down the hair loss with an anti-androgenic treatment and other treatment options in a man diagnosed in early stages with hair loss. In some cases, it is also shown that weakened hair with a tendency to fall, could be made thicker and more voluminous with treatment (67%). [2]

If we accept the slightest regression in the front-line as hair loss (Norwood Type II), Hamilton's study indicates 98%, whereas Norwood's attests 67% of the men at the age 50 have hair loss. [3,4]

It is getting more and more important to have an early diagnosis and immediate treatment of hair loss.

The main reason why Male Pattern Hair Loss (MPHL) is called "Andro-genetic" alopecia is its dependence on Androgens (Testosterone, dihydrotestosterone, androstenedion) which also has a genetic transmission pattern.

It is believed that inheritantly many different genes play a role in hair loss. [5] While one of these factors is the gene where 5-alpha-reductase enzyme is produced (both maternally and paternally transmitted), another important gene is located on the X chromosome (only maternal inheritance) and produces the androgen receptor gene, which has a genetic polymorphism that alters the receptor's activity, thus creating a genetic predisposition to hair loss.

Within these genes, the androgen receptor gene, which is only maternally transmitted, is shown to have the greatest association with androgenetic alopecia. [6] Although this condition could not explain the resemblance between fathers and sons, it is still valid and supported by the fact that male pattern baldness is never observed in patients with complete androgen insensitivity syndrome. [7]

Even though testosterone constitutes the majority of the androgens found in male blood, it is a metabolite of testosterone, dihydrotestosterone (DHT), which has the main role in hair loss. 5-alpha-reductase enzyme converts testosterone to the more active form, DHT. After this conversion, DHT binds to the androgen receptor and together they enter the cell nucleus and bind to DNA; resulting in the production of specific proteins. These produced proteins that corrupt the natural cycle of the hair follicles. The hair first miniaturizes, looses its pigment, rises within the skin and eventually falls.

There are two defined types of 5-alpha-reductase enzyme. Type I is found in kidneys, liver and brain and its function is not fully elucidated. On the other hand, Type II is found in the hair follicles of the scalp and also in prostate [8]. Finasteride treatment targets and affects Type II 5-alpha-reductase,so hair loss is reduced.

The hair follicles, which are found in the donor area in hair transplantation, are not affected by androgenic factors even if they have the same DNA composition as the front-line or vertex scalp follicles. Researchers propose different explanations for this matter, such as epigenetic alterations - DNA methylation differences. I think that, studies on this subject have great potential on finding an effective treatment for suppressing hair loss.

There are many different scales used for Male Pattern Hair Loss classification, but the most respected and popular scale is the Hamilton-Norwood scale, which is proposed in 1941.

Female Pattern Hair Loss

It is a general belief that women have fewer problems compared to men on hair loss issue. But my recent observations point to an increase in the complaints of women about loosing hair. Although Hamilton reported the ratio of women with hair loss at the age of 50 as 86% [3], other researchers documented this rate as 6% [11].

Hair loss related to androgens is also seen in women but it is rather uncommon compared to men. Underlying causes that change the androgen balance such as androgen secreting tumors (adrenal glands etc.) or polycystic ovarian syndrome might cause hair loss. In these cases there are certain conditions, which might accompany the hair loss, such as menstruational cycle disturbance, hirsutism, or acne.

Unlike men, hair loss in women does not begin from the front-line. It begins at the midscalp area and spreads from there. The hair first gets weaker, miniaturizes and eventually gets thinner.

I strongly believe that the genetic predisposition is the most important factor in Female Pattern Hair Loss. In addition to that, iron, zinc, magnesium and vitamin B deficiency, high or low levels of thyroid hormone, unbalanced diets, diffuse alopecia areata, chronic telogen effluvium, post-pregnancy, chronic illnesses, trichotillomania, Lupus (SLE) and especially severe psychological stress are frequently encountered causes of hair loss in women.

Female Pattern Hair Loss is first classified by Ludwig as I, II and III. [12] Later, Olsen made a classification separating the hair loss characteristics as early stage and pots-menopausal. [13]

References

[1] Camacho, F.M., et al. Psychological features of androgenetic alopecia. J Eur Acad Venerol, (2002), 71; 115-121.

[2] K.D. Kaufman, E.A. Olsen, D. Whiting, R. Savin, R. DeVillez and W. Bergfeld, Finasteride in the treatment of men with androgenetic alopecia. J Am Acad Dermatol 39 (1998), pp. 578–589.

[3] Hamilton JB., Patterned loss of hair in man; types and incidence. Ann N Y Acad Sci. 1951; 53(3):708-28.

[4] Norwood OT. Male pattern baldness: classification and incidence. South Med J. 1975; 68(11):1359-65.

[5] W. Küster and R. Happle, The inheritance of common baldness: two B or not two B?. J Am Acad Dermatol 11 (1984), pp. 921–926.

[6] Hillmer, A.M. et al. Genetic Variation in the Human Androgen Receptor Gene Is the Major Determinant of Common Early-Onset Androgenetic Alopecia. Am. J. Hum. Genet. 77 (2001),140–148.

[7] Griffin JE, Wilson JD. The androgen resistence syndromes: 5-alpha-reductase deficiency, testicular feminization and related syndromes. In: Scriver CR, Beaudet AL, Sly WS, Valle D, editors. The Metabolic Basis of Inherited Disease, 6th ed. New York: McGraw-Hill; 1989:1919-44.

[8] Chen W, Zouboulis CC, Orfanos CE. The 5 alpha-reductase system and its inhibitors. Recent development and its perspective in treating androgen-dependent skin disorders. Dermatology. (1996); 193(3):177-84.

[9] Marty E Sawaya and Vera H Price, Different Levels of 5-Reductase Type I and II, Aromatase, and Androgen Receptor in Hair Follicles of Women and Men with Androgenetic Alopecia. Journal of Investigative Dermatology (1997) 109, 296–300.

[10] Stephan Steckelbroeck et al., Characterization of the 5-Alpha-Reductase-3-Hydroxysteroid Dehydrogenase Complex in the Human Brain. The Journal of Clinical Endocrinology & Metabolism (2001) Vol. 86, No. 3 1324-1331.

[11] M.P. Birch , J.F. Messenger and A.G. Messenger., Hair density, hair diameter and the prevalence of female pattern hair loss. British Journal of Dermatology (2001), Vol. 144 Issue 2, 297 - 304.

[12] Ludwig, E., Classification of the types of androgenetic alopecia (common baldness) occurring in the female sex. British Journal of Dermatology (2006) Vol. 97 Issue 3, 247 - 254.

[13] Olsen, EA. Female pattern hair loss. J Am Acad Dermatol 2001; 45 (Suppl): S70-80.