Hair is considered one of the most defining aspects of human appearance.

Throughout history, hair has been used to make statements about health, beauty, and more. Alopecia, or hair loss, is a common and troubling problem in women that is often met with feelings of grief, self-consciousness, and frustration due to misdiagnosis or poor treatment options. Fortunately, our understanding of the various causes for female hair loss has increased in recent years, along with breakthroughs in treatment. Although androgenetic alopecia (AGA) is the most common cause of hair loss in women, there are many other causes. This post will review the most common causes of female hair loss and identify some treatment options.

History and Physical Examination

During our lifetime, each hair follicle undergoes continuous cycles of growth (anagen), resorption (catagen), and rest (telogen). The portion of hair that is seen is called the hair shaft. That which is below the surface of skin is the follicle. Hair loss can occur due to disturbances of the hair cycle, damage to the hair shaft, or disorders affecting the follicle. Thus, it is important to classify and diagnose the hair problem accurately.

A thorough review of a patient’s medical history (including medications, allergies, family history, and diet) is of utmost importance in identifying the cause of hair loss. A history of menses, pregnancy, and menopause is assessed. Specific hair-related questions that might be asked include:

“When did the hair loss start?”
“Was the hair loss sudden in onset or gradual?”
- If hair loss is sudden, there is likely a disruption of the hair cycle (telogen effluvium) whereas chronic (longstanding) hair loss may indicate an abnormality of the hair follicle (androgenetic alopecia).
“Where have you noticed the most hair loss?”
- When a patient presents for evaluation of hair loss, she may be referring to a single patch of alopecia (alopecia areata) or to extensive hair breakage from use of hair products (hair shaft damage). Patterned hair loss is seen most commonly in androgenetic alopecia.
“What is your normal hair care routine?"
- Hair care practices and use of hair cosmetics (i.e. bleaching, permanent waving) can be key factors in determining the cause of hair loss.

A detailed examination of the hair and scalp is performed with good lighting and magnification. Hair distribution over the rest of the body is also assessed to see if there is too little or too much hair in other areas.

Additional Testing

Certain labs can be quite helpful for determining the cause of female hair loss. Screening for thyroid abnormalities, low iron levels and anemia are important during a female hair loss evaluation. An iron panel and complete blood panel (CBC) are useful labs to obtain for women with heavy or long-lasting menses.

For women with androgenetic alopecia, extensive hormonal evaluation (such as measuring testosterone levels) is usually NOT needed unless any of the following conditions are present: irregular menses, infertility, hirsutism (excess body hair), severe acne, or galactorrhea.

Scalp biopsies can be used to make or confirm a diagnosis of alopecia and can be essential in guiding therapy.

Common Causes of Hair Loss and Treatment Options

Androgenetic alopecia (AGA)
Androgenetic Alopecia (AGA), or hereditary hair thinning, is the most common form of hair loss in humans. This condition is also known as male-pattern hair loss or as female-pattern hair thinning. Onset may occur in either sex at any time after puberty and the majority of thinning occurs in the teens, 20s, and 30s.

The cause of hereditary hair thinning is a gradual shrinkage of the hair follicle which occurs under the influence of androgen hormones. In fancy medical speak: the 5-alpha reductase enzyme converts testosterone to dihydrotestosterone (DHT) in scalp hair follicles. In genetically susceptible scalp hair follicles, DHT causes the gradual transformation of large hair follicles to a finer and shorter hair (this process is called “miniaturization”).

Women with hereditary thinning usually first notice a gradual thinning of their hair, mostly on the central scalp, and their scalp becomes more visible. The patient may notice that her “ponytail” is much smaller. This widespread thinning of the scalp can vary in extent, but it is extremely rare for a woman to become bare on top. Examination of the scalp will show a patterned hair loss with the frontal hairline usually intact but thinning mostly on the central scalp. Although androgens play an important role in AGA, levels of circulating androgens in men or women with AGA are usually normal. Thus, extensive laboratory tests are usually not needed if the woman with hereditary thinning has normal menses, pregnancies, and endocrine function.

Minoxidil topical solution (Rogaine®) is the only medication indicated for promoting hair growth in women with AGA, resulting in increase hair counts and total hair weight (i.e. re-enlarge the fine hairs). Women with AGA may also consider Spironolactone (Aldactone®) which has less evidence to back its efficacy, but might be a good choice in women with hirsutism (excess body hair).

Finasteride (Propecia®) is a medication (5-alpha reductase inhibitor) that decreases levels of DHT. Although it is by far the most effective treatment of androgenetic alopecia in men, it is NOT FDA-approved for women. Finasteride therapy for female-pattern hair loss has also been studied and has been shown to result in significant improvement in hair density and hair thickness at higher medication doses. It is therefore sometimes prescribed off-label. Pregnancy must be ruled out before initiating therapy and women should be maintained on strict birth control during treatment because it may pose a risk to the fetus.

Surgical options include hair transplantation where hair follicles are surgically moved from the “donor” occipital scalp (which is less susceptible to the effects of androgen hormones) to the thinned “recipient” areas (see photo above). Nonsurgical options include the use of camouflage techniques, such as creative coiffures (tinting, waving, and teasing) and scalp covers (powders or creams).

Other Causes
The second most common cause of female hair loss is thyroid disease (either hypothyroidism or hyperthyroidism). Thyroid disorders may result in dull, course, brittle hair or widespread hair loss. Hypothyroidism is about 10 times more common in women then men and particularly affects women between the ages of 40 to 60 years. Other common causes of hair loss include inadequate dietary protein, or low levels of vitamin D or iron.

Categories of drugs that may cause hair loss include: anticancer drugs, anticoagulant drugs, anticonvulsant drugs, beta blockers, tricyclic antidepressants, and oral contraceptives. Discontinuation of the medication is usually followed by hair regrowth. Oral contraceptives (birth control) must be selected carefully to avoid progestins with an androgenic effect.

Telogen Effluvium
Normally the majority of scalp hair is in the growth (anagen) phase, with a small percentage of hairs in the resting (telogen) phase being shed daily. On average, 100-200 hairs are shed daily. Under certain circumstances, a higher percentage of hairs cycle into the resting phase, and a woman may notice a sudden onset of marked shedding. Common causes include high fever, childbirth, severe infections, severe chronic illness, major surgery, thyroid disorder, crash diets, inadequate protein, and certain drugs. The shedding often starts months after the inciting cause but is always self-limited and reversible if the offending cause is corrected or resolved.

Damage to the Hair Shaft / Hair Breakage
Damage to the hair shaft by improper cosmetic techniques can cause hair breakage. There is little damage from normal dyeing, bleaching, waving or straightening. However, breakage can occur with too much tension during waving; waving solutions left on too long; or improperly neutralized, waving, and bleaching on the same day or too frequently. Other causes of hair breakage include excess tension in braids, ponytails, or cornrows.

Treatment of hair breakage usually requires alteration of the hair care routine. Hair loss is reversible if the cosmetic procedure is stopped and the hair is handled gently.

Hairstyles that pull on the hair, such as ponytails and braids, should be put in as loosely as possible and should be alternated with looser hairstyles. If there is a constant pull on the hair, damage to the hair follicle can occur, resulting in traction alopecia, which is seen especially along the sides of the scalp.
Shampooing, combing, and brushing too often can also damage hair, causing it to break. Using a cream rinse, conditioner, or leave-in conditioner with silicone will make the hair more manageable and easier to comb.
When hair is wet, it is more fragile, so vigorous rubbing with a towel, and rough combing and brushing should be avoided. Instead, the use of wide-toothed combs and brushes with smooth tips are recommended.
Also, using heat (blow- dryer, curling iron, flat iron) on wet hair can cause increased damage.

Alopecia Areata
Alopecia Areata is an autoimmune disease that affects almost 2% of the population in the United States. Inflammatory cells target the hair follicle, thus preventing hair growth. Typically a small round patch of hair is noticed; this patchy hair loss may regrow spontaneously. In other cases there can be extensive patchy hair loss, and in rare cases, there is loss of all scalp and body hair (Alopecia Areata Universalis).

Alopecia Areata occurs equally in males and females, at all ages, although young persons are affected most often. The nails may show track marks or pitting. Treatment for Alopecia Areata does not alter the natural course of the disease, nor does it prevent the formation of new patches of alopecia. Treatment options include one or a combination of the following: steroid injections, minoxidil, short contact anthralin, topical steroid, topical immunotherapy, light treatment, and oral steroids.

Hot Topic: Platelet-Rich Plasma for Hair Loss?

More recently, some clinicians have been offering platelet-rich plasma (PRP) for the treatment of hair loss. PRP is blood plasma that is drawn from the patient and has been enriched with platelets. Basically, it is a concentrated source of one’s own platelets. PRP contains several different growth factors and other cytokines that can stimulate healing of tissue. PRP therapy has been used in the past for dermatology, orthopedics and dentistry.

For hair loss, PRP is injected in the tissue where hair growth is desired and usually requires a series of treatments. Although a few studies have shown hair growth following PRP therapy, these are mostly small studies with a few patients enrolled in the study. As of 2016, no large-scale randomized controlled trials have confirmed the promise of PRP to treat androgenetic hair loss. At this point, more research needs to be done to explore the potential uses and effectiveness of PRP before we can conclude that PRP actually works for hair loss.

Summary
In summary, there are multiple causes for hair loss in women. In order to determine the exact cause of hair loss, a complete review of the patient’s medical history, detailed hair and scalp exam, and laboratory test(s) are necessary. Appropriate treatment and counseling can then be tailored to each patient’s needs.

References
1. Price VH. Treatment of hair loss. N Engl J Med 1999; 341: 964-973.
2. Mirmirani P. Top 10 misconceptions about androgenetic alopecia in women. Cosmetic Dermatology 2000; 30-31.
3. Sclafani AP, Azzi J. Platelet preparations for use in facial rejuvenation and wound healing: A critical review of current literature. Aesth Plast Surg 2015; 39: 495-505.

Further Reading:
Hair Loss Cure 2017 Ultimate Guide - We love this extensive guide on the wide range of hair loss treatment options created by one of our readers, Peggy. Check it out!

Sahar Nadimi, M.D. is a facial plastic surgeon and hair restoration specialist at the Chicago Hair Institute and Oakbrook Aesthetic, PC in Oakbrook Terrace, IL. As a fellowship trained facial plastic surgeon and board certified head and neck surgeon, Dr. Nadimi has dedicated her career to aesthetic facial surgery and is one of the few female surgeons in the country specializing in hair restoration.