Understanding Hair Loss in Women
Hair Loss (alopecia) is a very common problem seen in primary practice, and affects as many as 30% of adult women (1). The most common form of alopecia in women is female pattern hair loss (also called androgenic alopecia), which presents as a generalized reduction of hair around the crown and frontal scalp. Female pattern hair loss is caused by androgen excess, such as occurs in PCOS or around menopause. Hormonal shifts which occur postpartum may also result in hair thinning or loss. Other causes of hair loss are less commonly recognized, but may include undiagnosed hypothyroidism, insulin resistance, nutritional deficiencies, or stress. At any age, hair loss can have a major impact on a woman’s self-esteem and well being. A thorough workup and understanding of the etiology of this concern is crucial to treating it effectively.
Comprehensive Approach to Diagnosis
The cause of hair loss in women is often multi-factorial and a rigorous examination should include assessment of the following areas:
Dihydrotestosterone (DHT) is a testosterone metabolite, which is thought to be the main culprit in the pathogenesis of female pattern hair loss (androgenic alopecia) (2). Although circulating levels of DHT and other androgenic hormones may often be within the normal range for women with androgenic alopecia, enhanced tissue sensitivity to DHT is the generally accepted mechanism thought to explain this phenomenon. 5-alpha reductase, the enzyme responsible for the conversion of testosterone into DHT, is thought to preferentially accumulate in the hair follicle, leading to follicular miniaturization and shedding of the hair (3). Alternative hypotheses for the mechanism behind androgenic alopecia exist, such as one put forward by Ustuner in 2013. In his theory the increased DHT at the tissue level is seen as a mere response to hair thinning (3). The real cause of androgenic alopecia, according to Ustuner, is an increase in pressure exerted on the hair follicles. Normal aging, along with higher circulating levels of testosterone, act to thin the subcutaneous fat stores over the scalp, which weakens the support to the follicle. While this theory may seem controversial, its strength is that it does explain why hair loss tends to occur in specific locations over the scalp.
Androgen excess may occur at certain periods of a woman’s life, such as the perimenopause, when estrogen levels begin to decline. For other women, androgen excess may be more pervasive, such as in Polycystic ovarian syndrome (PCOS) or Congenital adrenal hyperplasia (CAH). In such cases, other clinical signs of high androgen levels may exist, such as the presence of acne or increased facial or body hair. In fact, according to a recent study, as many as 22% of women with PCOS suffer from androgenic alopecia (13).
Hair loss, especially alopecia areata, in thyroid dysfunction has been well established (8, 10, 11). In fact, abnormal thyroid function and anti-thyroid antibodies were found in 24% of patients with new onset alopecia areata (10). Furthermore, of these patients with thyroid dysfunction, 15% were diagnosed with subclinical hypothyroidism, a condition not commonly recognized in our conventional medical system (10). As one author states, “Every patient with (alopecia areata) should be screened for thyroid (function) and presence of thyroid autoantibodies even in absence of clinical manifestations suggestive of thyroid affection” (11).
Hair loss may also be associated with impaired glucose metabolism. In a Finnish study of postmenopausal women, hair loss was found to be more pronounced in women who also exhibited insulin resistance. Parameters associated with insulin resistance, such as increased abdominal obesity or circulating insulin levels, were much higher in women with extensive hair loss, when compared to those with minimal or no hair loss (12).
Intake of the following macro- and micronutrients should be evaluated in hair loss: protein, essential fatty acids, vitamin D, B vitamins including biotin, and certain minerals such as iron, zinc, selenium, copper and manganese.
Although not a commonly recognized cause, multiple studies have associated low ferritin levels (iron stores) with hair loss in women (5, 6, 7, 8).
Since hair is a non-essential tissue, marginal iron stores will be preferentially used by the heart and other vital organs. As such, a marginal ferritin level cannot correct hair loss. Rather, a ferritin level of at least 70 µg/L is recommended to allow for hair regrowth (9). This level is rare to find in women during their menstruating years, even if they regularly consume red meat. In one study, over 80% of the women affected by hair loss were found to have ferritin levels of less than 70 µg/L (7).
It is well established that vitamin D deficiency worsens hair loss, particularly in the autoimmune-mediated condition alopecia areata (14, 15). Zinc status also appears to play a significant role. Zinc levels were found to be significantly lower in patients with various types of hair loss, including alopecia areata, male pattern, female pattern hair loss, telogen effluvium (16) and hair loss associated with hypothyroidism (17). In another study, zinc, selenium, manganese and copper levels were all found to differ significantly in women with androgenic alopecia as compared to controls (18). This has led to a hypothesis that a disturbance in copper metabolism may play a specific role in the onset of androgenic alopecia (18).
Although difficult to quantify, the impact of psychological stress on hair loss should not be overlooked. Studies done on identical twins lend evidence to this statement, and allow us to understand that hair loss is not dictated by genetics alone. Instead, these studies demonstrate that women who either rate their overall stress levels as more severe, or who report a highly stressful life event, such divorce or separation, or suffering from a chronic health condition, are significantly more likely to experience hair loss or thinning (19).
The effect is reciprocating. Not only are women suffering from stress more likely to experience hair loss, but further, the quality of life of these women is often impacted very dramatically by the hair loss itself. In these cases, the treatment of hair loss must not only focus on correcting the underlying physiology, but also on addressing the woman’s emotional well being and coping mechanisms.
While the cause of hair loss can be complex and multifactorial, treating it effectively involves a comprehensive approach. The work-up for a woman suffering from hair loss should not overlook the significant impact of nutritional status, stress, as well as the potential involvement of multiple endocrine systems in this concern.
Part 2 of our Hair Loss in Women Series will Follow, so stay tuned!
If you have gone through a period of hair loss, what is the main cause for you?
- Sinclair R1, Patel M, Dawson TL Jr, Yazdabadi A, Yip L, Perez A, Rufaut NW. Hair loss in women: medical and cosmetic approaches to increase scalp hair fullness. Br J Dermatol. 2011 Dec;165 Suppl 3:12-8.
- Urysiak-Czubatka I, Kmieć ML, Broniarczyk-Dyła G. Assessment of the usefulness of dihydrotestosterone in the diagnostics of patients with androgenetic alopecia. Postepy Dermatol Alergol. 2014 Aug;31(4):207-15.
- Ustuner, ET. Cause of androgenic alopecia: crux of the matter. Plast Reconstr Surg Glob Open 2013;1:e64.
- Lourith N1, Kanlayavattanakul M. Hair loss and herbs for treatment. . J Cosmet Dermatol. 2013 Sep;12(3):210-22.
- Rasheed H1, Mahgoub D, Hegazy R, El-Komy M, Abdel Hay R, Hamid MA, Hamdy E. Serum ferritin and vitamin d in female hair loss: do they play a role? Skin Pharmacol Physiol. 2013;26(2):101-7.
- Moeinvaziri M1, Mansoori P, Holakooee K, Safaee Naraghi Z, Abbasi A. Iron status in diffuse telogen hair loss among women. K. Acta Dermatovenerol Croat. 2009;17(4):279-84.
- Park SY1, Na SY, Kim JH, Cho S, Lee JH. Iron plays a certain role in patterned hair loss. J Korean Med Sci. 2013 Jun;28(6):934-8.
- Perez-Mora N, Goren A, Velasco C, Bermudez F. Acute telogen effluvium onset event is associated with the presence of female androgenetic alopecia: potential therapeutic implications. Dermatol Ther. 2014 May-Jun;27(3):159-62.
- Rushton DH. Nutritional factors and hair loss. . Clin Exp Dermatol. 2002 Jul;27(5):396-404.
- Lyakhovitsky A1, Shemer A, Amichai B. Increased prevalence of thyroid disorders in patients with new onset alopecia areata. Australas J Dermatol. 2014 Oct 10. doi: 10.1111
- Bakry OA1, Basha MA1, El Shafiee MK2, Shehata WA1. Thyroid disorders associated with alopecia areata in egyptian patients. Indian J Dermatol. 2014 Jan;59(1):49-55.
- Matilainen V1, Laakso M, Hirsso P, Koskela P, Rajala U, Keinänen-Kiukaanniemi S. Hair loss, insulin resistance, and heredity in middle-aged women. A population-based study. . J Cardiovasc Risk. 2003 Jun;10(3):227-31.
- Quinn M1, Shinkai K2, Pasch L3, Kuzmich L4, Cedars M5, Huddleston H5. Prevalence of androgenic alopecia in patients with polycystic ovary syndrome and characterization of associated clinical and biochemical features. Fertil Steril. 2014 Apr;101(4):1129-34.
- Aksu Cerman A1, Sarikaya Solak S, Kivanc Altunay I.Vitamin D deficiency in alopecia areata. Br J Dermatol. 2014 Jun;170(6):1299-304.
- Mahamid M, Abu-Elhija O, Samamra M, Mahamid A, Nseir W. Association between vitamin D levels and alopecia areata. Isr Med Assoc J. 2014 Jun;16(6):367-70.
- Kil MS, Kim CW, Kim SS. Analysis of serum zinc and copper concentrations in hair loss. Ann Dermatol. 2013; 25(40):405-9.
- Betsy A, Binitha M, Sarita S. Zinc deficiency associated with hypothyroidism: an overlooked cause of severe alopecia. Int J Trichology. 2013; 5(1):40-2.
- Skalnaya MG, Tkachev VP. Trace elements content and hormonal profiles inwomen with androgenic alopecia. J Trace Elem Med Biol. 2001; 25 Suppl 1: S50-3.
- Gatherwright J1, Liu MT, Gliniak C, Totonchi A, Guyuron B. The contribution of endogenous and exogenous factors to female alopecia: a study of identical twins. Plast Reconstr Surg. 2012 Dec;130(6):1219-26.