On seeing a bald man walk past, most of us wouldn't take a second glance. But would this be the case if a bald woman walked past? It is doubtful. Hair loss - although distressing - is generally more accepted in men, despite women accounting for 40% of all hair loss sufferers in the US. In this Spotlight, we look at the main causes of hair loss in women, the emotional toll it can take and why research is lagging behind in treatment for female hair loss.
An enzyme called Type 2 5-alpha reductase - present in the oil glands of hair follicles, the skin organs that produce hair - helps convert testosterone to DHT. This derivative then binds to and shrinks hair follicles, killing healthy hair.
Because men have higher testosterone levels than women, they are likely to produce higher DHT levels, leading to increased hair loss. As such, men with androgenetic alopecia often experience a receding hairline which can progress to partial or complete baldness, while women tend to experience hair thinning on the top and sides of the scalp.
"Hair thinning in female pattern baldness is different from that of male pattern baldness in that the frontal hairline remains unaffected except for normal recession, which happens to everyone as time passes, and hair loss rarely progresses to total or near total baldness, as it may in men," Dr. Marc Glashofer, a dermatologist and fellow of the American Academy of Dermatology, explained to Medical News Today.
But androgenetic alopecia is not the only cause of hair loss in women.
What are the other common causes of hair loss in women?
The condition involves a sudden shift from hair growth or resting phases to the hair shedding phase, known as telogen. This can occur within 6 weeks to 3 months after a stressful experience.
According to Dr. Shani Francis, also a fellow of the American Academy of Dermatology and director of the Hair Disorders Center of Excellence at Northshore University HealthSystem in Illinois, telogen effluvium is much more common in women than men. "It is the typical 'shedding' that happens after childbirth in some women," she told us.
She added that some triggers of the condition - such as iron deficiency and changes in medication - are more likely to occur in women. "These triggers typically affect women more than men due to menstruation, the most common cause of iron deficiency in women, and the high prevalence of birth control use - some women change birth control quite frequently," she explained.
Traction alopecia is another form of hair loss that is more likely to occur in women. It is triggered by trauma to the hair follicles, most commonly through hair styling that continuously pulls at them - such as braiding, tight ponytails and hair extensions. "This type of hair loss is primarily seen in African-American patients," said Dr. Glashofer.
Another common cause of hair loss in both men and women is alopecia areata - an autoimmune disease that affects around 2% of the US population. The condition can be inherited; around 1 in 5 people who suffer from alopecia areata have a family member with the disorder.
It occurs when the immune system mistakenly attacks the cells in hair follicles, leading to hair loss on the scalp and other areas of the body. In alopecia areata, hair most commonly falls out in small patches. In some cases, however, the condition can lead to complete baldness.
Specific medical conditions - such as anemia and thyroid disorders - and the use of certain medications can also lead to hair loss.
The severe emotional impact of hair loss for women
It goes without saying that hair loss - regardless of gender - can be devastating. It can dent a person's self-esteem and negatively affect their overall quality of life.
"Studies on the psychosocial impact of hair loss have found patients' self-esteem, body image and self-confidence to be negatively impacted," Dr. Francis told MNT. "Known psychosocial complications include depression, low self-esteem, altered self-image and less frequent and enjoyable social engagement."
It seems experts are in agreement, however, that women are significantly more likely to suffer emotionally as a result of hair loss.
"Hair loss in a woman is so emotionally devastating that it can trigger a wide range of social and emotional issues that can negatively impact healthy daily living and overall quality of life. I have heard of women that retreat from social situations, have diminished work performance, and even alter their healthy living - avoiding exercise, overeating, not treating other medical illnesses - due to their hair loss," said Dr. Francis.
But why do women see a greater emotional impact from hair loss than men? According to Dr. Glashofer, it is down to society's perception of beauty. "Society unjustly puts an inordinate amount of pressure on beauty and a great deal of this comes from perceptions of hair," he told us.
Dr. Francis agrees. She told MNT:
"For a women, the hair is the crown, a symbol of beauty/pride. It is typically what a woman identifies with as being feminine or attractive to a mate. If this starts to diminish, it can be devastating to a woman's identity and self-esteem, especially when affected at an early age. For older women, hair loss is perceived as accelerated aging and women have to deal with a sense of loss of virility and sexual attraction to their mate as well.
"Due to societal perception differences, it is much more emotional for women, as there is limited cosmetic acceptance of a bald woman and increased societal pressure on a woman to be attractive. The negative quality of life is likely worse in women."
Drug companies 'aren't falling over themselves' to test new hair loss drugs in women
It is not only support from society that is lacking for women with hair loss; it seems the medical world has been ignoring these women's needs.
There is only one medication approved by the Food and Drug Administration (FDA) for women with androgenetic alopecia - a topical treatment called minoxidil that works by stimulating the hair follicles.
As well as minoxidil, men with androgenetic alopecia can be treated with another medication called finasteride. This drug works by dramatically lowering DHT levels, halting the progression of hair loss.
Due to conflicting clinical trials, finasteride has not yet been approved for the treatment of androgenetic alopecia in women. Some studies have found that finasteride can cause fetal mutations in women of childbearing age.
Such findings, Dr. Francis believes, have deterred researchers from testing hormonally-active medications in women with hair loss. Even the American Hair Loss Association admit that women are in a "catch-22" situation when it comes to hair loss treatment.
"While many drugs may work to some degree for some women, doctors are reluctant to prescribe them, and drug companies aren't exactly falling over themselves to test existing or new drugs specifically for their ability to prevent and treat female pattern baldness," they state.
Dr. Francis also notes that researchers tend to sway more toward testing hair loss medications in men because it is easier to measure their response to treatment; their hair is generally shorter so their scalp is easier to see. "Also, women have very diverse styling and grooming practices - that many are unwilling to change - which makes research harder to standardize," she added.
Recent progress in hair loss treatment for both men and women shows promise
But while it is clear that progress in hair loss treatment for women has been slow, recent research has shown some promise - making hair loss breakthroughs that could be applied to both sexes.
In August 2014, for example, a study published in the journal Nature Medicine revealed how a drug already approved by the FDA for a rare bone marrow disease restored hair growth in patients with alopecia areata.
The researchers found that ruxolitinib fully restored patients' hair within 4-5 months by preventing immune system cells from attacking the hair follicles.
"There are few tools in the arsenal for the treatment of alopecia areata that have any demonstrated efficacy. This is a major step forward in improving the standard of care for patients suffering from this devastating disease," commented Dr. David Bickers, of the Department of Dermatology at Columbia University Medical Center.
More recently, in January 2015, researchers from Sanford-Burnham Medical Research Institute in La Jolla, CA, claimed they have found a way to generate hair growth using human pluripotent stem cells.
Dr. Glashofer believes such research moves us a step closer to finding effective hair loss treatments for both men and women.
"Most recent groundbreaking hair research is attempting to define the biologic and genetic basis for certain types of hair loss. This obviously has value to both sexes," he told MNT. "Research attempting to utilize stem cells has broad implications for both hair loss treatments for men and woman and may have a role in treatment within the next decade."
While it is good news that progress is being made in terms of treatment for female hair loss, it is clear that greater awareness is needed of how the condition can affect women - particularly how it can affect them emotionally.
Dr. Francis points out that most people may not realize the extent to which these women are suffering, pointing out that many of them cover up their hair loss with wigs, scalp concealer and other cosmetic devices.
Again, this comes down to the fact that hair loss is generally more accepted in men. "Men are much more willing to shave the rest of the heads if hair loss starts to take over and this is cosmetically acceptable and in some cases quite attractive. Women are not able to have the same societal support for a smooth bald head," Dr. Francis told MNT.
It should not be the case that female hair loss is deemed unacceptable. Scottish model and TV presenter Gail Porter - who was diagnosed with alopecia in 2005, which led to complete baldness - is testament to the fact women are beautiful with or without hair. In an interview with the Scottish Express last year, Porter spoke of her challenges with hair loss while being in the public eye.
"As much as they say that people don't judge you on the way you look on TV, they do," She told the newspaper. "They [television bosses] say things like 'Would you consider wearing a wig?' "When I refuse, they say 'Oh, okay, we'll get back to you.' In other words, 'We're not having you because you have no hair.' I'm in a good place and I'm not going to wear a wig for anybody."