What causes hair loss in men? Signs of thinning hair before baldness.
Working-age man experiencing hair loss; falling out in clumps during work hours; hair loss in the office.
Hair loss characteristics in men:
Male hair loss presents with a range of patterns, timelines and accompanying symptoms. Understanding these characteristics helps in identifying causes and choosing appropriate assessment or treatment. Common features include:
Pattern of loss
Androgenetic alopecia (male-pattern baldness): thinning typically begins at the hairline and temples (receding hairline) and/or the crown (vertex). Over time these areas can expand and may eventually meet, producing the classic horseshoe pattern of hair remaining at the sides and back.
Diffuse thinning: generalised reduction in hair density across the scalp rather than discrete bald patches; often linked to telogen effluvium or chronic telogen effluvium.
Patchy loss: clearly demarcated round or oval patches of complete hair loss, characteristic of alopecia areata.
Traction alopecia: hair loss in areas subject to repeated tension (hairline, temples) from certain hairstyles or grooming practices.
Age of onset
Can begin in late teens or early twenties for androgenetic alopecia, though onset varies. Telogen effluvium and alopecia areata can occur at any age.
Progression and rate
Androgenetic alopecia usually progresses gradually over years; rate influenced by genetics and hormonal sensitivity.
Telogen effluvium produces relatively rapid shedding over weeks to months, often after a trigger (illness, surgery, stress, medication).
Alopecia areata can be sudden, with patchy loss occurring over days to weeks and potential for spontaneous regrowth.
Hair shaft and follicle changes
Miniaturisation: in androgenetic alopecia, terminal hairs gradually become finer, shorter and less pigmented as follicles miniaturise.
Increased telogen hairs: in telogen effluvium a higher proportion of hairs enter the resting (telogen) phase and are shed.
Exclamation-mark hairs, cadaverised hairs and smooth bald skin are seen in alopecia areata in early stages.
Scalp condition and symptoms
Typically no scarring in common forms (androgenetic, telogen effluvium, alopecia areata), meaning follicles remain capable of regrowth.
Scarring (cicatricial) alopecia is less common in men and involves inflammation that destroys follicles; affected areas may show scarring, loss of follicular openings and sometimes pain or burning.
Scalp may be normal, or show signs of inflammation, scaling, redness or infection depending on cause.
Associated signs and systemic links
Family history: strong hereditary component in androgenetic alopecia.
Hormonal associations: sensitivity to dihydrotestosterone (DHT) is central to male-pattern hair loss.
Medical triggers: thyroid disease, nutritional deficiencies (iron, vitamin D, protein), systemic illness, severe stress, certain medications can precipitate telogen effluvium.
Autoimmune association: alopecia areata may be associated with other autoimmune conditions (thyroid disease, vitiligo).
Hair shedding versus hair loss
Increased daily shedding (more hairs in the comb or shower) can signal an active process; a careful hair assessment help distinguish shedding from permanent loss.
Common types of hair loss in men:
Androgenetic alopecia (male pattern baldness)
The most common form of hair loss in men.
Caused by genetic sensitivity to dihydrotestosterone (DHT), which shortens the hair growth cycle and miniaturises hair follicles.
Typical pattern: receding hairline (temporal recession) and thinning at the crown, which can progress to extensive balding.
Onset often begins in late teens to early 20s, but progression varies.
Treatments: topical minoxidil, oral finasteride, low-level laser therapy, and hair transplant surgery; management is guided by diagnosis and patient preference.
Alopecia areata
An autoimmune condition in which the immune system attacks hair follicles.
Presents as one or more well-defined, round or oval patches of complete hair loss on the scalp (can also affect beard and body hair).
Course is unpredictable: spontaneous regrowth is possible, but relapses and progression to more extensive forms (alopecia totalis/universalis) can occur.
Treatments aim to suppress the immune response locally or systemically: potent topical or intralesional corticosteroids, topical immunotherapy, and in some cases systemic immunomodulators for severe disease.
Telogen effluvium
Diffuse, temporary hair shedding due to a higher-than-normal proportion of hairs entering the telogen (resting) phase.
Common triggers: severe physical or psychological stress, illness, surgery, major weight loss, certain medications, postpartum hormonal changes, or nutritional deficiencies.
Typically occurs 2–4 months after the triggering event and often resolves over several months once the cause is addressed.
Management: identify and treat the trigger, correct nutritional deficiencies, and provide supportive hair care; topical or systemic treatments may be considered if shedding persists.
Anagen effluvium
Rapid hair loss during the anagen (growth) phase, most commonly caused by cytotoxic chemotherapy and radiotherapy.
Hair loss can be widespread and occurs within days to weeks of exposure.
Often reversible if the hair follicle stem cells are spared; regrowth usually begins several months after the insult ends.
Preventive measures (such as scalp cooling during chemotherapy) and supportive care are the main approaches.
Traction alopecia
Hair loss caused by chronic tension on hair shafts from certain hairstyles (tight ponytails, braids, hair extensions) or hair practices.
Initially reversible if diagnosed early and tension is removed; prolonged traction can cause follicular damage and permanent loss, particularly at the frontal hairline.
Management: change hairstyling practices, gentle hair care, and, for established scarring, surgical options may be considered.
Scarring (cicatricial) alopecia
A group of conditions in which inflammation destroys hair follicles and replaces them with scar tissue, leading to permanent hair loss.
Can be primary (inflammatory process targets follicles) or secondary (injury, burns, infections).
Clinical features include patchy hair loss, perifollicular redness, scaling, pustules or loss of follicular openings.
Early diagnosis and anti-inflammatory treatment (topical/systemic corticosteroids, immunosuppressants) aim to halt progression; hair restoration may be possible once disease is inactive.
Diffused androgenetic-like thinning (combination patterns)
Some men show a mix of androgenetic alopecia with diffuse thinning or telogen effluvium superimposed, leading to more noticeable shedding and thinning over a wider area.
Management requires addressing both the underlying genetic pattern and any reversible triggers.
Other less common causes
Nutritional deficiencies (iron, vitamin D, biotin in severe deficiency), thyroid disease, chronic systemic illness, infections (tinea capitis in adults is less common but possible), medications (e.g., anticoagulants, retinoids), and lifestyle factors can all contribute to hair loss.
Male Pattern Hair Loss
Overview Male pattern hair loss (MPHL), also known as androgenetic alopecia, is the most common cause of hair loss in men. It is characterised by a predictable pattern of hair thinning — usually a receding hairline and thinning at the crown — and is driven by a combination of genetic predisposition and the effects of androgens (male hormones).
Causes and mechanism
Genetics: Family history is the strongest risk factor. Multiple genes influence susceptibility; inheritance can come from either parent.
Androgens: Dihydrotestosterone (DHT), a derivative of testosterone, binds to hair follicle receptors and shortens the hair growth cycle (anagen). Over time follicles miniaturise, producing finer, shorter hair until they may stop producing visible hair.
Age: Incidence increases with age. Onset commonly begins in the late teens to early 20s but can occur later.
Other contributing factors: While MPHL is primarily genetic and hormonal, factors such as stress, smoking, nutritional deficiencies and certain medications can influence progression.
DHT hormone and hair loss in men
DHT (dihydrotestosterone) and hair loss in men
What is DHT? DHT (dihydrotestosterone) is an androgen — a male sex hormone — produced from testosterone by the enzyme 5α‑reductase. It is more potent than testosterone in binding to androgen receptors in tissues including the scalp, prostate and skin.
How DHT affects hair
Sensitivity of hair follicles: Male pattern hair loss (androgenetic alopecia) is primarily driven by genetic sensitivity of scalp hair follicles to DHT. Follicles with increased sensitivity undergo progressive miniaturisation: the hair shaft becomes finer, growth phase (anagen) shortens, and the follicle eventually produces vellus‑like hairs or stops producing hair.
Local effect: DHT acts locally at the follicle level. Systemic blood levels of DHT do not necessarily predict hair loss; rather, the amount of 5α‑reductase activity and androgen receptor sensitivity within the scalp determine the effect.
Pattern and timing: Typical male pattern hair loss presents with a receding hairline and thinning at the crown. The degree and age of onset vary according to genetic predisposition.
Contributing factors
Genetics: Family history is the strongest predictor. Multiple genes influence follicle sensitivity to DHT.
Age: Incidence increases with age; many men show some degree of androgenetic alopecia by middle age.
Hormonal milieu: Higher local DHT production or increased 5α‑reductase expression in the scalp can expedite hair loss.
Other influences: Nutrition, stress, autoimmune conditions, medications and scalp health can modulate progression but do not replace DHT‑mediated mechanisms in androgenetic alopecia.
Assessment and Management Guidelines:
An examination by a hair and scalp specialist (Trichologist) is necessary to diagnose the underlying cause.
If you are concerned about hair loss, schedule an appointment with a hair and scalp specialist for an assessment and to develop an appropriate treatment plan based on your individual cause and hair condition.
