What are the causes of alopecia (hair loss) in females?

From the Guidelines

Hair loss in women can be caused by several factors including hormonal changes, genetic predisposition, medical conditions, medications, and lifestyle factors, with female pattern hair loss (androgenetic alopecia) being the most common cause, affecting about 40% of women by age 50. The causes of alopecia in females are multifactorial and can be attributed to various factors such as:

• Hormonal changes: Hormonal fluctuations during menopause, pregnancy, or polycystic ovary syndrome (PCOS) can lead to hair loss 1
• Genetic predisposition: Family history of alopecia areata or androgenetic alopecia can increase the risk of developing hair loss 1
• Medical conditions: Thyroid disorders, autoimmune diseases like alopecia areata, and nutritional deficiencies (particularly iron, vitamin D, and zinc) can contribute to hair loss 1
• Medications: Certain antidepressants, blood thinners, chemotherapy drugs, and some birth control pills may cause hair shedding as a side effect
• Lifestyle factors: Hairstyling practices like tight ponytails, excessive heat styling, and chemical treatments can damage hair follicles

According to the most recent study 1, serum vitamin D, zinc, and folate levels tend to be lower in patients with alopecia areata compared to controls. However, the evidence for iron deficiency as a cause of hair loss is conflicting, and further research is needed to determine its role in alopecia areata management 1. Addressing underlying medical conditions and ensuring adequate nutrition are essential parts of management, and women experiencing hair loss should consult a dermatologist for proper diagnosis and personalized treatment recommendations. Treatment options may include topical minoxidil (Rogaine) 2% or 5% applied twice daily, oral medications like spironolactone (50-200mg daily) or finasteride in select cases, platelet-rich plasma injections, low-level laser therapy, and hair transplantation for severe cases.

From the Research

Causes of Alopecia in Females

The causes of alopecia, or hair loss, in females are multifactorial and can be attributed to various factors, including:

• Genetic factors, which play a significant role in the development of androgenetic alopecia 2, 3, 4
• Systemic androgens, which can lead to follicular miniaturization and hair loss 2, 3
• Hormonal changes, which can regulate hair loss and hair growth 5
• Androgen-independent mechanisms, which can also contribute to female pattern hair loss (FPHL) 3
• Genetic polymorphisms involving the androgen and estrogen receptors, which can predict treatment response to anti-androgens 3
• Age, as the prevalence of FPHL increases with advancing age 3
• Metabolic syndrome and cardiovascular risk factors, which should be screened for in patients with FPHL 3

Types of Hair Loss

There are different types of hair loss that can affect females, including:

• Female pattern hair loss (FPHL), characterized by diffuse reduction in hair density over the crown and frontal scalp with retention of the frontal hairline 3
• Telogen effluvium, a common cause of hair loss in women, which can be chronic or acute 3, 6
• Androgenetic alopecia, a common type of hair loss influenced by genetic factors and systemic androgens 2

Pathophysiology

The pathophysiology of FPHL is not completely understood and is thought to be multifactorial, involving a combination of genetic, hormonal, and environmental factors 3, 4. Additionally, microbiomata, oxidative stress, and microinflammation are suspected to play a role in the development of pattern hair loss 4.