What causes hair loss in women?

Thyroid problems

Irregular amounts of thyroid hormones within the body can cause a multitude of problems, including hair loss. Having healthy thyroid hormone levels is important for your hair as well as for your overall health. Dr. Ruthie Harper will perform a complete testing for optimal thyroid function-critical for healthy hair as part of your evaluation.

Polycystic ovary syndrome (PCOS)

An evaluation for polycystic ovary syndrome (PCOS) is important as well. Women who experience hormonal imbalances could show higher levels of androgens (male hormones) which could result in extra hair on the face and body. This ultimately causes hair on the scalp to thin, as well as irregular menstrual cycles, acne, and weight gain.

Autoimmune hair loss

Often called alopecia areata, this condition causes hair to fall out in patches. It’s caused by the body’s own immune system mistakenly attacking healthy hair follicles. In most cases, the damage is not permanent. When alopecia areata occurs, the missing patches usually grow back in 6 months to a year. In rare cases, people may lose all of the hair on their scalp and body, a condition called alopecia universalis.

Female pattern hair loss (Androgenetic alopecia)

If your mother, aunts, or grandmothers have experienced hair loss, it’s likely that you will experience it as well. Typically, each time a normal hair follicle is shed, it’s replaced by hair that is equal in size. However, women with female-pattern hair loss have new hair that is finer and thinner. Eventually the hair follicles shrink and may stop producing hair altogether.

According to the American Academy of Dermatology, 50% of women see this in their late 50s or 60s, although it can happen at any time.

Fungal infections (Ringworm)

Ringworm is a fungal infection that can affect the scalp, triggering a distinct pattern of hair loss that occurs in itchy, round patches. Bald areas can appear scaly and red. This condition is usually treated with antifungal medication. Family members should be checked for symptoms too since the fungus is easily spread by direct contact.

Hormonal shifts

During menopause, changing estrogen, progesterone, and testosterone levels can create imbalances where hair loss is accelerated and new hair growth is slowed.


Many women notice fuller hair during pregnancy due to hormonal changes that keep resting hairs from falling out as they normally would. After childbirth, when hormones suddenly shift, a sudden and sometimes alarming amount of hair may be lost all at one time. It may take up to 2 years for hair to return to normal without proper care and intervention.


Many women experiencing hair thinning or hair loss are often iron deficient. Replenishing the iron stores of balding patients increases their chances of hair growth in most cases, and stops hair loss in nearly every patient.

However, too much iron can be toxic so it’s important to follow the advice of a medical professional. Reasons why low iron levels might be present in the body include, heavy periods, postpartum blood loss, ulcers, and inflammation of the stomach with bleeding of the digestive tract.

Medication, such as birth control pills

Birth control pills have a little known side effect in the form of a higher potential for hair loss in women with a family history of hair loss. Other medications linked to hair loss include blood thinners and medicines that treat high blood pressure, heart disease, arthritis, and depression.


You may lose more than just weight with a crash diet. Many people noticed hair loss within 3-6 months after losing more than 15 pounds, especially in weight loss programs that don’t include proper nutrition and vitamin supplementation.

Hair styling

Certain hairstyles such as extensions, cornrows, or tight ponytails can irritate the scalp and hair loss in a condition often called traction alopecia. Certain treatments such as hair dyes, chemical treatments, bad brushes, tight rollers, blow dryers, and flat irons can result in damage, breakage, and further hair loss. Removing the source of this irritation is critical due to how long-term use of these styles can cause scarring of the scalp and could lead to permanent hair loss.


This emotional/behavioral condition causes a compulsive tendency to pull hair from the scalp, brows, or eyelashes. Most of the hair pulling tends to occur in selected areas causing patchy hair loss instead of diffuse hair loss. Hair loss due to this cause cannot be treated effectively due to the psychological or emotional problems that must be addressed first.

Cancer treatment

Chemotherapy and radiation therapy are the most common side effects of cancer treatment. Both treatments can cause damage to hair follicles, often resulting in dramatic hair loss. Damage is almost always short-lived, however, a healthy hair regrowth regimen can be supported by a comprehensive hair restoration program.


Extreme physical or emotional stress from surgery or illness can cause a sudden loss of hair called telogen effluvium. This occurs when the hair follicles stop growing and life dormant, falling out within 2 to 3 months. Being that telogen effluvium is often caused by stress, surgery, or illness, hair growth is typically restored within 6 to 9 months.

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