Hair loss is one of the most emotionally distressing conditions a woman can experience — and yet it is one of the most underdiagnosed and undertreated areas in dermatology. Many women struggling with thinning hair are told by their primary care providers that it’s “just stress” or “normal with age” and sent home without further evaluation. Often, there is a specific, treatable cause that a board-certified dermatologist can identify — and the sooner it’s found, the better the outcome.
This post covers the most common causes of hair loss in women, explains what a proper dermatologic evaluation looks like, and outlines the treatment options available today — including newer therapies that have changed what’s possible for many patients.
How Common Is Female Hair Loss?
Hair loss affects an estimated 40% of women by age 50, and up to 55% by age 70, according to data published in the Journal of the American Academy of Dermatology. Despite its prevalence, it receives far less public attention than male pattern baldness — leaving many women feeling isolated with a problem they’re not sure how to address or even talk about.
Female hair loss is rarely just one thing. It is often multifactorial — meaning multiple contributing causes exist simultaneously — which is one reason why self-diagnosis and over-the-counter treatment shopping usually fail. A proper evaluation by a dermatologist who specializes in hair disorders makes an enormous difference in both diagnosis accuracy and treatment outcomes.
The Most Common Causes of Hair Loss in Women
Female Pattern Hair Loss (FPHL / Androgenetic Alopecia)
The most common cause of hair loss in women, FPHL is driven by a genetic sensitivity to dihydrotestosterone (DHT) — a byproduct of testosterone metabolism — that gradually miniaturizes hair follicles over time. Unlike male pattern baldness, which often causes a receding hairline and crown baldness, female pattern hair loss typically presents as diffuse thinning at the top of the scalp with relative preservation of the frontal hairline. Women notice their part widening, less volume at the crown, and sometimes a visible scalp through the hair. FPHL is progressive without treatment.
Telogen Effluvium (TE)
Telogen effluvium is diffuse hair shedding triggered by a physiological stressor that shifts a large number of hair follicles from the active growth phase (anagen) into the resting and shedding phase (telogen) simultaneously. The trigger typically occurred 2 to 4 months before the shedding becomes noticeable — meaning a woman who had COVID-19, surgery, significant blood loss, or major psychological stress in April may notice excessive shedding in July. Common triggers include illness (COVID-19 in particular has been associated with significant TE), childbirth (postpartum telogen effluvium), crash dieting or rapid weight loss, major surgery, thyroid dysfunction, and iron deficiency. TE is usually temporary but can become chronic if the underlying trigger is not identified and addressed.
Alopecia Areata
An autoimmune condition in which the immune system attacks hair follicles, causing sudden, patchy hair loss. Patches are typically smooth and round, occurring on the scalp or elsewhere on the body. Alopecia areata can range from a single small patch to complete loss of all scalp hair (alopecia totalis) or all body hair (alopecia universalis). It can be emotionally devastating and unpredictable in its course. Newer JAK inhibitor medications — including baricitinib, the first FDA-approved systemic treatment specifically for severe alopecia areata — have dramatically changed the outlook for patients with extensive disease.
Iron Deficiency
Iron deficiency — with or without anemia — is one of the most commonly missed contributors to female hair loss. Ferritin (the body’s stored iron) levels below approximately 40 ng/mL have been associated with increased hair shedding in multiple studies, even when hemoglobin remains normal. Women of reproductive age, vegetarians, and those with heavy menstrual periods are at particular risk. Iron supplementation in deficient patients can meaningfully improve shedding over 4 to 6 months.
Thyroid Disease
Both hypothyroidism and hyperthyroidism can cause diffuse hair thinning and loss. Thyroid-related hair loss typically improves significantly once thyroid function is restored to normal with appropriate medical management. Thyroid function testing (TSH, free T4) is a standard part of the hair loss workup at Dehesa Dermatology.
Hormonal Changes
Hormonal transitions — including postpartum hormonal shifts, perimenopause, menopause, and discontinuation of hormonal contraceptives — can all trigger or worsen hair loss. Polycystic ovary syndrome (PCOS), associated with elevated androgens, is a common cause of androgenetic alopecia in women of reproductive age.
Traction Alopecia
Chronic tension on hair follicles from tight hairstyles — braids, weaves, extensions, tight ponytails, cornrows — can cause progressive hair loss at the margins of the scalp (temporal hairline, nape of neck). Traction alopecia is initially reversible but becomes permanent if the tension is maintained long enough to permanently scar the follicle. Early recognition and hairstyle modification are essential.
Scarring Alopecias
A group of conditions — including lichen planopilaris, frontal fibrosing alopecia, and discoid lupus — that permanently destroy hair follicles through inflammation and replace them with scar tissue. These require prompt diagnosis and aggressive treatment to halt progression, as lost hair in scarred areas does not regrow. They are among the conditions most commonly misdiagnosed as simple FPHL.
What a Proper Hair Loss Evaluation Looks Like
A thorough hair loss evaluation at Dehesa Dermatology includes:
- Detailed patient history: Onset and pattern of loss, associated symptoms, recent stressors, medical history, current medications, family history of hair loss, diet, and hair care practices.
- Scalp dermoscopy (trichoscopy): Magnified examination of the scalp and hair follicles that allows assessment of follicle density, miniaturization patterns, inflammatory signs, and features specific to particular diagnoses — dramatically improving diagnostic accuracy compared to the naked eye alone.
- Pull test: Assessment of the number of hairs shed with gentle traction — helps distinguish active shedding from stable loss.
- Targeted laboratory testing: Including complete blood count, ferritin, thyroid function (TSH, free T4), vitamin D, zinc, and hormone panels as clinically indicated.
- Scalp biopsy: When scarring alopecia, alopecia areata, or other inflammatory conditions are suspected, a small scalp punch biopsy provides definitive histological diagnosis.
Treatment Options for Women with Hair Loss
Minoxidil — available topically (2% and 5%) and in low-dose oral formulations — remains the most widely used treatment for female pattern hair loss and telogen effluvium. It prolongs the anagen growth phase and has been shown to increase hair density and reduce shedding in clinical trials. Oral low-dose minoxidil (0.25 to 1 mg daily) has gained significant traction in recent years for its convenience and efficacy.
Spironolactone is an anti-androgen medication that blocks DHT’s effect on hair follicles. It is particularly effective for women with androgenetic alopecia, PCOS-related hair loss, and hormonal hair thinning. Typically prescribed at 50 to 200 mg daily.
Platelet-Rich Plasma (PRP) Therapy involves drawing a small blood sample, concentrating the growth factors through centrifugation, and injecting them into the scalp to stimulate dormant follicles. PRP is used as a complement to other treatments for androgenetic alopecia and telogen effluvium.
JAK Inhibitors — both topical (ruxolitinib) and oral (baricitinib, ruxolitinib) formulations — represent a major advance for alopecia areata, with FDA-approved options now available for severe disease.
Addressing underlying causes — correcting iron deficiency, normalizing thyroid function, managing hormonal imbalances, and modifying hairstyling practices — produces meaningful hair recovery in many patients when identified and treated promptly.
When to See a Dermatologist
Don’t wait until hair loss is severe. The earlier a cause is identified and treatment begins, the better the outcome — particularly for conditions involving progressive follicle miniaturization or scarring. See a dermatologist promptly if you notice:
- A visibly widening part or increased scalp show at the crown
- Increased hair on your brush, pillow, or in the shower drain
- Smooth, round patches of hair loss anywhere on the scalp
- Hair loss along the frontal hairline or temporal areas
- Scalp symptoms including itching, burning, or tenderness in areas of loss
At Dehesa Dermatology in Clovis, CA, we evaluate and treat all forms of female hair loss with the full range of diagnostic tools and therapeutic options described above. We serve patients from Clovis, Fresno, Madera, Selma, Sanger, Reedley, and throughout the Central Valley. Dr. Dehesa is fully bilingual in English and Spanish.
Call (559) 951-9000 or visit dehesadermatology.com to schedule your hair loss evaluation. For additional information on hair loss causes and treatments, the American Academy of Dermatology’s patient resources on alopecia are an excellent starting point.
