Why is my hair falling out?

Men get all the attention when it comes to hair loss. The fact is, it’s common in women, too — but it doesn’t necessarily look the same.  

“Hair loss in women looks different than in men,” says Erinolaoluwa Araoye, MD, a Geisinger dermatologist. “Instead of a bald spot or receding hairline, most women will notice a wider part or thinner hair overall, and they tend to lose less hair than men.”

Some shedding is part of the normal hair cycle, but ongoing thinning or patchy areas can point to an underlying reason that warrants attention. There are many causes of hair loss in women, and it’s often not just one thing. Getting to the root of the problem is the first step in slowing hair loss or even reversing it. 

Hair growth lifecycle

Just as seasons change, each hair follicle on your scalp cycles through stages. And the balance between growth and rest phases determines density and fullness.

The hair cycle includes 3 main phases: 

• Anagen: Hair is actively growing during this phase. It lasts between 2 and 8 years and sets the potential length. About 90% of the hair on your head is in this growing phase.
• Catagen: A transition phase that lasts about 2 to 3 weeks. The follicle shrinks and disconnects from its blood supply. Hair stops growing and prepares to shed.
• Telogen: A resting phase that lasts about 3 months. At the end of it, older hairs are released and replaced by new anagen hairs to begin a new growth cycle.

“If the growth cycle is interrupted and follicles become inflamed, lack nutrients or are affected by hormones, they may shorten the anagen phase, shrink (produce finer hairs) or enter telogen prematurely,” says Dr. Araoye. “This can lead to thinning.”

Causes of hair loss in women

Many factors can influence hair growth and fullness: from genetics to hormonal imbalances to your diet. Identifying the root cause and primary triggers will help guide effective treatment to help slow progression or even reverse hair loss. 

Here are the 7 most common causes of hair loss in women:

Genetics

Female pattern baldness, medically known as androgenetic alopecia, is the most common cause of hair loss. It happens as a natural part of aging and can be inherited from your father or mother. Over time, follicles shrink and produce finer, shorter hairs or stop growing hair altogether. Women may notice a widening part and thinning at the crown of their head, while the frontal hairline is often unaffected.

In many cases, female pattern hair loss doesn’t permanently damage the hair follicle, so hair can grow back with treatment. But while genetics set the likelihood of hair loss, age and hormones can shape the pace of progression. Early intervention is key to help maintain fullness and reverse hair loss. 

Hormonal changes

Hormones control the hair cycle, growth and thickness of your hair and extreme changes can cause permanent or temporary hair loss in women. Hormone shifts after pregnancy can cause postpartum telogen effluvium, where new moms may have temporary shedding due to follicles spending more time in the telogen phase. Menopause also can lead to gradual thinning at the crown or part line as estrogen and progesterone levels drop.

In addition, health conditions that cause hormone imbalances like thyroid disorders (hypothyroidism or hyperthyroidism) and PCOS (polycystic ovary syndrome) can disrupt the hair cycle and lead to shedding.

“Thankfully, once hormone balance is restored — either naturally or by medication — hair usually regains fullness in about 6 to 9 months,” says Dr. Araoye. 

Autoimmune conditions and prescription meds

Certain autoimmune conditions, such as alopecia areata and lupus, can cause sudden, round patches of hair loss in women. The disruption in the hair growth cycle can be due to inflammation or the immune system mistakenly attacking hair follicles, which can shrink or stop hair growth altogether. 

“For some autoimmune conditions, early treatment is important to prevent permanent damage and hair loss,” says Dr. Araoye. 

Several medications can also lead to hair loss as a side effect. Prescriptions used to treat cancer, arthritis, depression and heart problems may trigger temporary shedding or thinning. 

Changing the drug or dosage can help reverse it. If you have cancer, try wearing a cooling cap before, during and after treatment to help prevent hair loss.

Scalp infections

Scalp infections like scalp ringworm, seborrheic dermatitis and folliculitis (follicle infection) can cause redness, scaling and patchy hair loss. 

Medicated shampoo or topical therapy can help. And keeping your scalp clean with regular washing, gentle exfoliation and addressing dandruff can also improve comfort and reduce breakage. In most cases, hair usually grows back once the infection is cleared.

Vitamin deficiencies

Hair follicles require a healthy dose of nutrients to function properly. Iron is necessary to carry oxygen-rich blood to hair follicles — and a deficiency in iron can cause hair loss in women. Other deficiencies in vitamins A and D, biotin, zinc, B12 and folate also can contribute to shedding or brittle hair. And because hair is primarily protein, women need adequate amounts in their diets to support stronger strands.  

A balanced diet rich in lean proteins, whole grains, fruits, vegetables and healthy fats like salmon and olive oil is the foundation for healthy hair. If you suspect your diet could be to blame, lab testing can determine deficiencies. A targeted diet and/or supplement plan can reverse hair loss.  

Stress

Physical or emotional stress can push follicles from the anagen phase into telogen, medically known as telogen effluvium, and lead to increased shedding. This often follows major life events like a divorce or death, job loss, pregnancy or serious illness. 

Thankfully, once stress is relieved or you recover from the illness, most women see regrowth in about 3 to 6 months. Medication can help if hair doesn’t return on its own.

“Improving stress management like prioritizing sleep, regular physical activity and practicing mindfulness can help normalize the hair cycle and protect your overall health in the process,” says Dr. Araoye. 

Hair styling practices

The techniques and products you use regularly to style your hair can either protect or weaken it. Excessive heat, frequent bleaching and harsh chemical treatments can break hair. Wearing tight braids, ponytails or other hairstyles can stress the follicles and over time cause traction alopecia, which leads to thinning or bald spots.

In most cases, when you limit high-heat tools, space out chemical services and rotate hairstyles, your hair will grow back. However, it’s possible for these practices to damage the follicle and cause permanent hair loss. 

Signs of hair loss? When to seek care

Seeing hair in your hairbrush or shower drain doesn’t necessarily mean you have a problem. Most women shed 50 to 100 hairs daily as part of the normal cycle. But if you notice persistent shedding over several months, a widening part, patchy areas or unusually finer hair, schedule an appointment.

A dermatologist can assess your symptoms, review medications and run a few tests to diagnose the cause of your hair loss and offer tailored treatment options. The good news: There are effective therapies that reverse or slow down hair loss in women. 

Hair loss treatment for women

Treatment will depend on the underlying cause of hair loss. 

Topical minoxidil is often used for female pattern hair loss. And sometimes, switching medications or treating the underlying condition or hormone imbalance is enough for the hair to grow back. Lifestyle factors like eating a healthy diet, managing stress and relaxing hairstyles can help, too. 

For severe cases, you and your provider may consider advanced treatments, including:

• Laser therapy
• Microneedling
• Platelet-rich plasma therapy
• Hair-transplant surgery

Your provider may recommend a combination of treatments to slow hair loss or reverse it. What works best for you depends on the type of hair loss, medical history and goals. 

“Early action can help preserve your hair density and prevent permanent damage to the follicles,” says Dr. Araoye. “If you’re concerned about hair changes, don’t wait to schedule an appointment. There are effective treatments to regrow your hair — and regain your confidence.”

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