Hair Loss (Alopecia)

Hair loss, known clinically as alopecia, thins hair in some, changes the hairline in others, and can lead to partial or total baldness. While it’s usually hereditary and a result of aging (androgenetic alopecia, or pattern baldness), it can also be the result of physical or emotional stress, a side effect of cancer treatment or other medications, or due to other factors.

Though hair loss isn’t a medical emergency, it can be distressing, impacting self-esteem and mental health. However, certain medications and other therapies may help manage the problem, and some types resolve independently. This article discusses the symptoms and possible causes of alopecia and provides a quick breakdown of how it can be treated.

Alopecia on a person's head

Reproduced with permission from © DermNet New Zealand and © Raimo Suhonen 2023.

Symptoms of Hair Loss

The exact pattern of hair loss depends on what’s causing it, and it can vary based on sex.

Androgenetic alopecia is the most common type. It arises more gradually, as you lose about 100 hair follicles a day (the typical scalp has 100,000). Male pattern baldness starts above the temples and works its away around the edges and top of the head. In women, the hair usually thins more evenly, and there’s less of a change along the hairline.

However, nervous habits, burns, ringworm (tinea capitis), or other dermatological conditions can bring on bald patches or circles. Furthermore, physical or emotional stress, radiation therapy, and some medications can cause hair to fall out in clumps.      

Phases of Hair Loss

At its core, hair loss occurs due to disruptions of the body’s hair follicle growth cycle. Whether balding or not, your hair goes through these three phases:

  • Anagen phase: This is when the hair continues to grow; the anagen phase can last several years.   
  • Catagen phase: For a period of 10 days, the hair stops growing and disconnects from the follicle. Follicles stabilize the hair.
  • The telogen phase: The hair rests for up to three months, before eventually falling out. As part of the natural cycle, people lose 50 to 100 hairs a day in this phase.

Basically, when this cycle is disrupted, hair falls out without being regenerated. In most cases, this is a gradual process, though it can set on more quickly in some people.

Types of Hair Loss and Their Causes

Common types of hair loss are androgenetic alopecia, telogen effluvium, anagen effluvium, tinea capitis, and alopecia areata.

Androgenetic Alopecia

Most people who experience hair loss have inherited the condition from a parent, something commonly called pattern baldness.

While male pattern baldness is more common, women can also be affected. About 80% of men and 38% of women over age 70 experience it. Female pattern baldness causes more diffuse (widespread) thinning and is generally more gradual in its progression, whereas in men, pattern baldness causes partial or complete hair loss.

Telogen Effluvium

Hair loss can also occur from physical and emotional stress. Clinically referred to as telogen effluvium, it arises when hair goes into a resting phase without subsequently starting new growth. This phase often is temporary. Causes include:

Though it rarely causes complete baldness, telogen effluvium causes very rapid hair loss. Most people see hair regrowth around three months after its trigger. 

Anagen Effluvium

Hair loss can also be a side effect of certain drugs or treatments. This type of baldness, called anagen effluvium, usually reverses once the therapy is over or you stop taking the medication.  This is particularly the case with chemotherapy and other cancer-treating drugs, such as:

Additionally, many other types of drugs also bring on baldness, including:

Tinea Capitis

Tinea capitis (scalp ringworm) is hair loss due to a fungal infection. It is most often seen in children. It leads to hair falling out in (often) circular patches, which can grow over time. The exposed skin in these cases is red, flaky, itchy, and can be covered in sores.

Alopecia Areata

This type of hair loss occurs due to an autoimmune disorder (such as lupus or fibromyalgia), in which the immune system attacks hair follicles and prevents their growth. Alopecia areata can lead to total baldness.

Other Causes

Other causes of hair loss include:

  • Burns: Scarring from a burn can prevent hair from growing in the area of the scar.
  • Tumor of ovaries or adrenal glands: Ovarian overproduction of androgens (sex hormones that can trigger the development of traditionally male traits) is a condition that causes the ovaries to make too much testosterone. Eventually, this will lead to a female developing male characteristics, which can include male pattern baldness.
  • Trichotillomania: This is a hair-pulling disorder in which someone will repeatedly pluck hairs from their head and/or body.
  • Hair products: Trichorrhexis nodosa is hair loss caused by damage to the hair. It arises due to excessive hair brushing, heat treatments, too tight hairstyles, or harsh treatments, such as bleaching or dying.
  • Exposure to toxins: Exposure to high levels of certain toxins can also bring on hair loss. These include bismuth, arsenic, and gold.

Are There Diagnostic Tests?

Most kinds of hair loss, such as pattern baldness and both telogen and anagen effluvium, can be diagnosed based on symptoms and medical history alone. However, other tests may be needed:

  • Blood tests to screen for illnesses that may be causing issues
  • Pull tests, assessing the strength of follicles
  • Skin biopsy to remove a sample of your scalp for testing in a lab


When the hair loss is caused by illness, treating the underlying cause allows hair to grow back. Discontinuing medications or radiation therapy and chemotherapy can also reverse balding. In other cases, medications and dermatological therapies can help. Here’s a breakdown of what’s done about hair loss.


Effective for both male and female pattern baldness, application of Rogaine (topical minoxidil) on the scalp can spur hair regrowth. For males, 2% or 5% concentrations work, while for females, 2% is recommended. You will need to use this treatment indefinitely; if you stop, you will lose the regrown hair.

Alpha Reductase Inhibitors

Male pattern baldness can be treated with inhibitors of alpha-reductase, an enzyme associated with steroid production. Drugs like Propecia (finasteride) and Avodart (dutasteride) are prescribed to reduce or stop the progression of hair loss.

Intralesional Corticoids

Injections of corticosteroids help in cases of alopecia areata, which is when the hair loss is caused by autoimmune dysfunction. In a clinical procedure, dermatologists inject these drugs just below the skin of affected areas in the scalp to spur regrowth.

Antifungal Medications

Tinea capitis (ringworm) treatments depend on the type of fungus causing the infection. For Trichophyton infection, oral Lamisil (terbinafine), Sporanox (itraconazole), and Diflucan (fluconazole) may be prescribed. There’s some evidence that Gris-PEG (griseofulvin) is effective against another fungus, Microsporum. These may need to be applied as a shampoo.

Janus Kinase (JAK) Inhibitors

In June 2022, the Food and Drug Administration (FDA) approved Olumiant (baricitinib) for the treatment of adults with severe alopecia areata. It is a JAK inhibitor that works by selectively blocking immune signals that cause inflammation. Olumiant is taken by mouth and is the first systemic treatment approved for alopecia areata. It is also approved for the treatment of adults with moderate to severe rheumatoid arthritis.

Therapies for Trichotillomania

When hair loss is caused by compulsive hair pulling or twisting (trichotillomania), cognitive behavioral therapy (CBT), a form of talk therapy, may be recommended. This therapy involves focusing on the reasons behind why this compulsion developed, and working on strategies to regulate unwanted behaviors.

Another treatment option is serotonin reuptake inhibitors (SSRIs). While more research is needed, drugs like the antidepressants Lexapro (ecitalopram) and Prozac (fluoxetine) can help.

Other Therapies

A number of other medical, cosmetic, and at-home therapies may also help manage hair loss. These include:

  • Antiandrogens (testosterone blockers)
  • Progesterone or estrogen therapy (for female pattern baldness)
  • Vitamins B12, C, D, and zinc
  • Hair transplantation (hair from another part of the head is surgically grafted for restoration)
  • Laser and light therapy, which has been recently approved by the Food and Drug Administration (FDA)

If hair loss is causing you significant distress and affecting your quality of life, seek out support from others. Along with friends and family, talking to a therapist or mental health counselor can help, as can joining support groups.

Know What You’re Taking

If you try supplements for hair loss, make sure you know what exactly you’re taking. While some vitamins and minerals help, excess amounts of vitamins A, E, and selenium can actually make matters worse.

Home Management

At-home strategies won’t reverse hair loss, but they can help manage it. Here’s what you should keep in mind:

  • Gentle washing: Use a mild shampoo and moisturizer when washing your hair and try leave-in detanglers or conditioners. Dry with an absorbent towel rather than a blow-dryer.
  • Don’t treat your hair at home: Stop using at-home bleaching, dying, or other kinds of hair treatments. Work with salons that have professionals able to inspect your scalp and cater their services to your needs.
  • Avoid heat: Limit it or stop using curling irons, heating lamps, blow-dryers, and other tools that expose your hair to heat.
  • Looser hairstyles: Braids, ponytails, and other styles that involve pulling hair tightly can also cause or worsen hair loss. Easing that tension can certainly help.
  • Easy brushing: Only use a comb or brush when you really need to style your hair. Be gentle and use slow, consistent strokes.
  • Diet: Eat a healthy, well-balanced diet, and be sure you are getting enough calories each day. Insufficient nutrition can contribute to hair loss.

When to See a Healthcare Provider

While hair loss is rarely a medical emergency, it can be a sign of something more serious. Contact your healthcare provider if you experience:

  • Unusual or irregular pattern of hair loss
  • Significant hair loss at a young age
  • Pain, itching, or inflammation of the scalp
  • Infected areas on the scalp
  • Bald spots on the eyebrows or beard
  • Hair loss accompanied by weight gain, fatigue, muscle weakness, or chills
  • You’re a cisgender woman with male pattern baldness, acne, an abnormal menstrual cycle, or facial hair


If you are experiencing hair loss, you are not alone—35 million men and 21 million women in the United States are also experiencing hair loss.


Hair loss, known clinically as alopecia, is very common and can arise for many reasons. In many cases, it’s hereditary and a natural result of aging. However, emotional and physical stress, medical treatments, and infections of the scalp can also contribute to it.

Treatments, such as minoxidil, can spur hair regrowth, and others can help manage underlying causes of hair loss. Lifestyle changes and cosmetic treatments can also help.

Frequently Asked Questions

  • What causes hair loss?

    Most cases of baldness are inherited or the result of aging. However, hair loss can also arise due to physical or emotional shock, chemotherapy or radiation treatment, or as a side effect of certain medications. Infections of the scalp, thyroid conditions, vitamin or mineral deficiency, autoimmune disorders (such as lupus), and compulsive hair pulling (trichotillomania) are among the other causes.

  • What can I do to manage thinning hair?

    Treatment and management approaches to hair loss depend on the underlying cause. Medications, such as Rogaine (minoxidil) and Propecia (finasteride) can help with pattern baldness. Prescribed hormone therapies and steroid injections can also help, as can taking certain supplements, and making changes to your hair care routine. Hair transplantation surgery and laser therapy to spur hair growth are additional cosmetic options.   

  • Can a stressful event cause hair loss?

    Physical stress, as in severe illness, or emotional shock can cause a type of hair loss called telogen effluvium. While this causes hair to fall out rapidly, typically on top of the scalp, it continues to grow back. As such, this type is usually reversible, with hair growing back within 12 months.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. NYU Langone Health. Types of hair loss.

  3. Phillips T, Slomiany W, Allison R. Hair loss: common causes and treatment. Am Fam Physician. 2017;96(6):371-378.

  4. University of Florida Health. Ovarian overproduction of androgens.

  5. Yee B, Tong Y, Goldenberg A, Hata T. Efficacy of different concentrations of intralesional triamcinolone acetonide for alopecia areata: a systematic review and meta-analysis. J Am Acad Dermatol. 2020;82(4):1018-1021. doi:10.1016/j.jaad.2019.11.066

  6. Food and Drug Administration. Olumiant label

  7. American Academy of Dermatology. Hair loss: tips for managing.

  8. The Hair Society. Hair loss statistics.

Additional Reading

By Mark Gurarie
Mark Gurarie is a freelance writer, editor, and adjunct lecturer of writing composition at George Washington University.