Why am I losing my hair?

Aug 16

Written By Crystal

Most hair loss is caused by genetics (androgenetic alopecia), but hormones, stress, illness, nutrition, and scalp conditions can also contribute. A proper diagnosis starts with history, scalp/follicle assessment, and lab screening when indicated.

Hair loss, or alopecia, is a multifactorial condition with several well-established causes. The most common is genetic predisposition, specifically androgenetic alopecia, which presents as patterned hair thinning in both men and women and is driven by inherited sensitivity of hair follicles to androgens.[1-4] Hormonal changes are another major contributor: thyroid disorders (both hypo- and hyperthyroidism), postpartum hormonal shifts, and polycystic ovary syndrome (PCOS) can disrupt the hair cycle and lead to diffuse shedding or thinning.[1][4-5]

Acute or chronic stress, major illness, and surgery can trigger telogen effluvium, a form of hair loss where a larger proportion of hair follicles enter the resting phase and shed, typically several months after the inciting event.[1][3][6] Nutritional deficiencies—especially iron, vitamin D, and zinc—are recognized contributors, particularly in women and those with restrictive diets.[1][5][7] Medications such as chemotherapy agents, anticoagulants, and retinoids are also implicated in hair loss, often causing abrupt or diffuse shedding.[1][3][5]

Scalp conditions, including seborrheic dermatitis, psoriasis, and fungal infections, can cause inflammation and damage to hair follicles, resulting in localized or diffuse hair loss.[1-2][5] Diagnosis relies on a systematic approach: a detailed history (including family history, medication use, and recent illnesses), scalp and hair examination (often with dermoscopy or scalp photography), and targeted laboratory screening for iron status, thyroid function, and vitamin D levels when indicated.[1-2][7-9]

Early diagnosis is crucial, as prompt intervention can slow progression and preserve hair density.[2][4-5] Recommended next steps include booking a trichology or dermatology consultation for scalp assessment and preparing a list of medications, recent lab results, and family history to facilitate a personalized evaluation and management plan.

Key points

Common causes: genetics, hormones (thyroid, postpartum, PCOS), medication, stress, illness, nutritional gaps, scalp inflammation.
Pattern, speed of loss, and miniaturisation help pinpoint the cause.
Early diagnosis preserves more hair.