What Are the Causes of Hair Loss in Women

Over 50 percent of women experience a type of hair loss in their lifetime. (1) Hair loss can be tough to cope with. It can have a significant impact on a woman’s confidence levels and sense of self-worth. Sudden hair loss in women can be particularly devastating. 

You might notice hair loss if your hair is thinning, the part in your hair is widening, or if bald spots start to appear. Hair loss can also manifest as excess shedding. If you lose over 125 hairs a day on average, you’re likely experiencing a form of hair loss. (1) 

So, why does women’s hair fall out? Hair loss in women can occur for many different reasons. It can be due to the way you style or treat your hair, medications you’re taking, other medical conditions, including specific types of alopecia, and more. 

What Is the Main Reason for Hair Loss in Females?

The most common cause of hair loss in women is androgenic alopecia, also known as pattern hair loss. This type of alopecia is actually the most common cause of hair loss in both men and women. 

In women with this condition, hair typically starts to thin at the top of the head. This change is most noticeable where you part your hair. Over time, diffuse thinning and hair loss occur across the top of the head. However, women’s hairlines generally remain unaffected, unlike the hairline receding as is common with men. (1) 

Why Do Womens’ Hairs Fall Out?

Pattern hair loss in women is caused by a mixture of genetics and hormonal changes. One hormone in particular – an androgen called dihydrotestosterone (DHT) – is thought to be responsible for hair loss. (2) 

Androgens are usually beneficial, supporting sexual development and bodily functions like hair growth and sex drive. But in women with pattern hair loss, DHT binds to the hair follicles, causing them to shrink over time. This is called follicular miniaturization. Female pattern hair also causes the hair growth cycle to be shortened, resulting in thinner, weaker strands of hair. (2) 

Female Pattern Hair Loss Treatments

There are several treatments available for hair loss, including topical solutions, light therapy devices, nutraceutical supplements, and clinic-based procedures that promote hair regeneration. Out of these, two options – a topical medication called minoxidil and low-level laser therapy – are approved by the FDA for female pattern hair loss.

Minoxidil is a topical treatment that works by increasing blood flow to the scalp. This increases the size of hair follicles and encourages thicker, healthier hair strands to grow. Minoxidil is sold as a liquid and foam in concentrations of 2 and 5 percent. Both concentrations are approved to treat female pattern hair loss and must be applied daily to remain effective. (1) 

Laser hair therapy, also known as low-level light therapy (LLLT), involves the use of LEDs or lasers. Light therapy treatments are usually administered using a comb, cap, hood, or helmet. It’s thought that the light from these devices can be absorbed into the scalp, stimulating hair follicles and encouraging hair growth. (3) 

Other treatment options are available; these alternatives have yet to be approved by the FDA. Treatment alternatives include hair transplantation surgeries and platelet-rich plasma treatments, which are both procedures that need to be obtained in a hair loss clinic. Women also often consider nutraceutical treatments, like hair growth supplements or solutions, though studies showing the effectiveness of such products are limited. (3,4)  

Other Reasons for Hair Loss in Women

Female androgenic alopecia is a common cause of hair loss, but there are a range of other reasons women’s hair falls out. These include alopecias like autoimmune hair loss, stress-related hair loss, scarring alopecias, traction alopecia, and medication-related hair loss. The word alopecia is simply a scientific term for a type of hair loss. 

Alopecia Areata

Alopecia areata is an autoimmune condition. When it occurs, the body’s immune system mistakenly attacks hair follicles. This condition usually results in circular patches of hair loss. (5,6)

While alopecia areata typically affects the scalp, this condition has the potential to affect any part of the body where hair grows, including the eyelashes, eyebrows, and genital regions. Around 5 percent of women with this condition experience complete hair loss on the scalp, while 1 percent end up with complete hair loss all over their bodies. (5,6) 

Alopecia areata is technically reversible, especially in cases that are less severe. This is because it’s a non-scarring form of alopecia. While the body is attacking hair follicles and causing hair loss, it’s not actually damaging the follicles themselves. (5,6)

Treatment for this condition varies depending on the extent of the hair loss. If alopecia areata affects less than 50 percent of the scalp, it will likely be treated with corticosteroid injections. If it’s more advanced, other treatments such as topical minoxidil, topical immunotherapy, ultraviolet radiation treatments, and immunosuppressants may be used. (6) 

Telogen Effluvium

Telogen effluvium is a form of hair loss caused by stress or a traumatic event, which may be emotional or physical. For example, stress-related hair loss can be due to the loss of a loved one, a physical illness, a major surgery, or rapid weight loss. It can also be caused by some medications and nutritional deficiencies. (6,7) 

Stress-related hair loss is caused by a disruption to the hair growth cycle. When this happens, a large number of hairs move from the growth phase into the resting phase. Usually, this wouldn’t be an issue as the next hair growth cycle would start. But in this case, they don’t – which means that hairs fall out and new hairs don’t replace them. (6,7) 

With telogen effluvium, women experience hair thinning rather than bald patches, particularly around the temples and crown of the head. Hair loss is usually noticeable as it occurs in larger than average amounts – usually, loss of over 125 hairs a day is indicative of this condition.

Telogen effluvium typically begins 3 months after the event or issue that triggered hair loss. Once the ‘stressor’ that caused the condition is dealt with, hair can start to regrow (which usually occurs about 6 months later). While certain issues – like nutrient deficiencies – need to be actively corrected, most forms of telogen effluvium in women can resolve on their own, without any specific treatment. (6,7) 

Chemotherapy-Induced Alopecia 

Chemotherapy-induced alopecia is hair loss caused by chemotherapy treatment. It’s also known as anagen effluvium. Chemotherapy drugs attack cancer cells growing in the body. But unfortunately, they can also attack other cells, including the ones in hair follicles that promote hair growth. (8) 

Chemotherapy-induced hair loss typically begins between 2 and 4 weeks after starting chemotherapy. Some people lose patches of hair, while others may experience hair thinning all over the scalp. It’s common for it to result in complete hair loss. (8) 

Usually, once chemotherapy treatment stops, hair starts to grow back a few weeks later. This means that a hair loss treatment isn’t usually required. Some people choose to use scalp cooling caps during chemotherapy, which can slow blood flow to the scalp. These caps slow the effect chemotherapy drugs have on hair follicles, which may stop or reduce hair loss. (8) 

Scarring Alopecias

Scarring alopecias are caused by an inflammatory response that destroys hair follicles. This causes scar tissue to form, which prevents future hair regrowth. Hair loss can start gradually or may happen quickly. This type of hair loss is often accompanied by symptoms like swelling, redness, and irritation. (5,7)

There are lots of different types of scarring alopecias. Frontal fibrosing alopecia occurs most commonly in women after they go through menopause. It typically causes a receding hairline, though it can also affect other areas of the body, including the eyebrows. (5,7) 

Central centrifugal cicatricial alopecia is more common in women of African American descent. It’s partially caused by the repeated use of certain hair products and hairstyling techniques, though genetics is also thought to play a role. Hair loss usually starts in the middle of the scalp and spreads out from there. (7,9)

Lichen planopilaris is particularly common in young women. It causes patches of hair loss and makes the scalp in those regions appear smooth and shiny. People with this condition often report other symptoms, like itchiness, discomfort, burning, pain, and tenderness. (7,10)

Treatments for all scarring alopecias focus on slowing or stopping the progression of the condition. In all cases, immunosuppressive and anti-inflammatory medications may help with these types of hair loss. That being said, once the hair is lost and scarring has affected follicles, hair loss in the affected areas can’t be reversed. Because of this, women affected by scarring alopecias may prefer using cosmetic solutions, like wigs or hairpieces. (7,10) 

Traction Alopecia

When hair is tied up too tightly regularly, like in tight ponytails or braids, it can pull too much and cause strain, affecting hair follicles. This can damage hair strands and put stress on hair follicles, causing hair loss over time. This type of hair loss, known as traction alopecia, can lead to bald spots and hair thinning. (7) 

Friction can also cause hair loss. Hair damage can be caused by wearing tight hats, hair bands, or poor-quality hair ties. (5) 

If caught early – and the hairstyle or accessory causing the issue is changed – hair can regrow. However, once the hair follicles are damaged, traction alopecia can result in permanent hair loss. (5,7) 

Other Potential Causes of Women’s Hair Loss

As well as hair loss conditions, there are also other potential causes of hair loss in women, like lifestyle and age-related causes. Additionally, hair loss can be caused by other medical conditions. Some of these are specific to women, while others can be an issue for any gender. 

Age

Hair loss is particularly common in women over the age of 40. As humans age, hair growth naturally slows down. This means that some age-related hair loss is normal. 

As they grow older, women may notice that their hairlines start to recede and their hair becomes thinner. Certain treatments, like minoxidil, can help improve hair health and support the regrowth of lost hair. (1,5)

Hormonal Imbalances and Changes

Hormonal imbalances can be one of the main causes of thinning hair in women. Menopause is a significant time of change for women, during which lots of hormonal shifts happen. 

During menopause, levels of hormones called estrogen and progesterone fall, and levels of androgens increase. These changes can cause hair follicles to shrink and hair to grow more slowly, causing thinning. It may also cause hair growth in new areas of the body. (1) 

Polycystic ovary syndrome (PCOS) is another condition that causes hormonal hair loss in women. This condition causes cysts on a woman’s ovaries, among other symptoms. Thinning hair is a common symptom that’s caused by PCOS. Fortunately, several treatments can help manage this condition. (1,5) 

Underlying Medical Conditions

More than one medical condition makes women’s hair fall out. For example, thyroid disease can cause hair to fall out in clumps. And sexually transmitted infections, like syphilis, can cause patchy hair loss. Even some chronic illnesses can lead to hair loss. 

Skin and scalp conditions are particularly common issues that can result in hair loss. Skin infections can cause inflamed skin, damage follicles, and cause bald spots. And skin conditions, like psoriasis, can spread to the scalp and cause temporary hair loss. 

Treatment and outcomes for these types of hair loss depend on the specific medical condition. Usually, treating the source of the issue also resolves the associated hair loss. (5)

Medications

Some people experience hair loss as a side effect of medications. A wide range of medications can cause hair loss. Typically once the medication is stopped or changed, hair will regrow over time. But remember: You should never stop taking a medication without talking to your doctor first. (5) 

Trichotillomania

Trichotillomania is a condition that causes a strong urge to pull out your hair. It’s typically related to mental health issues and times of stress or trauma. It affects young girls and women more than men. (5,11)

Hair that’s pulled out may regrow if hair follicles haven’t been damaged. But repeatedly pulling out hairs will cause permanent damage over time. Treatment typically involves psychological therapy to help stop the behavior. (5,11) 

Nutrient Deficiencies

When your body doesn’t get enough of the vitamins, minerals, and amino acids it needs, hair loss may occur. This is particularly known to happen if your diet lacks nutrients like biotin, iron, protein, or zinc. Once nutrient deficiencies are addressed, hair can usually regrow without a hair loss treatment. 

Before you start buying hair growth supplements or some other multivitamin, be aware that too much of certain nutrients can be bad, too. It’s possible for excessive levels of vitamins and minerals (particularly those that aren’t water-soluble and build up in your body) to be detrimental and also cause hair loss. (5) 

Poison and Other Toxins

Taking too many supplements can throw off the balance of nutrients in your body, causing hair loss. While they’re healthy in small amounts, certain nutrients can be toxic when they build up in the body in large amounts. For example, an excess of vitamin A or selenium can be particularly troublesome. (5)

Other poisons and toxins – like accidentally ingesting or inhaling toxins – can lead to hair loss over time. Arsenic, thallium, mercury, lithium, and large amounts of warfarin are particularly dangerous. Fortunately, once the toxin is identified and you are no longer exposed to it, your health improves and hair typically regrows. (5) 

What Causes Hair Loss in Women?

The most common cause of hair loss in women is female pattern hair loss. But hair loss in women can be caused by many other types of alopecia, as well as age, medical conditions, medications, and lifestyle factors. 

Regardless of the reasons a woman’s hair falls out, it can be a devastating thing to deal with. Thankfully, there are many treatments and ways to cope that can help women regain their confidence. 

Women experiencing female androgenic alopecia can use an FDA-approved treatment, like topical minoxidil or LLLT, to treat their hair loss. If hair loss is extensive, they may also consider clinic-based procedures like platelet-rich plasma treatments or surgical procedures like hair transplants. 

If women are affected by scarring alopecias, it is important for them to try to obtain treatment before permanent damage is done to the hair follicle. If permanent hair loss has already occurred, cosmetic solutions, like wearing wigs or hairpieces, may be good alternative solutions.

Some types of hair loss, such as telogen effluvium, trichotillomania, traction alopecia, and medication-related hair loss, don’t require a hair loss treatment. Instead, the original cause of the condition needs to be addressed for hair loss to stop and hair to regrow.