From the Guidelines

Alopecia in women is primarily caused by chemotherapy, endocrine therapies, and autoimmune diseases.

Chemotherapy-induced alopecia (CIA) is a common cause of hair loss in women, resulting in diffuse grade 2 alopecia on the entire scalp, and is driven by a p53-mediated apoptosis of hair matrix keratinocytes and stem cells 1.
Endocrine therapies, such as aromatase inhibitors (AIs), can cause endocrine-induced alopecia (EIA), characterized by grade 1 alopecia primarily on the crown of the scalp and recession of the frontal and bitemporal hairline, particularly in post-menopausal women 1.
Autoimmune diseases, such as alopecia areata, can also cause hair loss in women, with a genetic predisposition and associations with major histocompatibility complex (MHC) and cytokine genes, suggesting a multifactorial genetic predisposition 1.

Type and dose of chemotherapy: The severity of CIA mainly depends on the type, dose, method of administration, and time of intervals between infusions 1.
Hormonal changes: Endocrine therapies can cause excessive hair growth in androgen-dependent areas of the body in women (hirsutism) and may contribute to female-pattern hair loss 1.
Genetic predisposition: A family history of alopecia areata and associations with certain genes, including MHC and cytokine genes, can increase the risk of developing autoimmune-related alopecia 1.

From the Research

Female pattern hair loss, also known as female androgenetic alopecia, is the main cause of hair loss in adult women 2, 3, 4, 5
The pathogenesis of female pattern hair loss is not yet fully understood, but it is influenced by genetic, hormonal, and environmental factors 2
Androgens play a role in the development of female pattern hair loss, with dihydrotestosterone binding to the androgen receptor and activating genes responsible for the transformation of large terminal follicles to miniaturized follicles 3
Other factors that may contribute to female pattern hair loss include:
- Genetic predisposition 3, 6
- Hormonal imbalances, such as polycystic ovarian syndrome (PCOS), hyperprolactinemia, and adrenal hyperplasia 5
- Environmental factors, although the exact mechanisms are not well understood 2

Female pattern hair loss is characterized by a diffuse thinning of hair over the central scalp, with retention of the frontal hairline 3, 4, 5
The condition can have a significant psychological impact, leading to anxiety and depression 5
Diagnosis is typically made clinically, with trichoscopy and scalp biopsy used to confirm the diagnosis in some cases 5

Topical minoxidil solution is a common treatment for female pattern hair loss, with efficacy shown in double-blind studies 3, 5
Oral anti-androgens may also be used to treat female pattern hair loss, particularly in women with hyperandrogenism 5
Other treatment options, such as microneedling, low-level laser therapy, and autologous fat transfer, are also being explored 4, 6