The Causes of Hair Loss in Men and Women
Shedding 50–100 hairs a day is normal — but when does it become clinical hair loss? A clear guide to the biological triggers in men and women, and when to seek advice.
Finding an unusual amount of hair in the shower drain or on your hairbrush can be an unsettling experience. Hair loss is an incredibly common concern across the UK, affecting a significant portion of both men and women at some stage in their lives.
It is completely normal to shed between 50 and 100 hairs a day. However, when shedding noticeably exceeds this amount or regrowth fails to keep pace, it marks the transition from standard physiological cycles to clinical hair loss. Understanding the root cause is the first step toward effective intervention.
The visual difference: pattern hair loss
Pattern hair loss in men
- Receding hairline at the temples (an M-shape).
- Thinning at the crown (the vertex).
- A horseshoe-shaped ring of remaining hair.
Pattern hair loss in women
- Diffuse thinning across the entire scalp.
- Widening of the part line.
- Reduced density rather than distinct bald patches.
Core causes of hair loss in men
Over 95% of male hair loss is due to male pattern baldness. This hereditary condition makes hair follicles hypersensitive to a hormone called dihydrotestosterone (DHT), a byproduct of testosterone. DHT binds to the follicles, causing them to shrink over time (a process called miniaturisation). Eventually the hair becomes so thin and fine that it stops breaking through the skin.
Core causes of hair loss in women
Hormonal fluctuations
Significant shifts during pregnancy, menopause, or when starting or stopping birth control can lead to temporary but noticeable thinning as the body's androgen balance changes.
Nutritional deficiencies
Low levels of iron (ferritin), vitamin D and B12 are primary triggers. Hair is a non-essential tissue, so the body redirects nutrients to vital organs first when levels are low.
Thyroid conditions
Both overactive and underactive thyroid glands can disrupt the hair growth cycle, often resulting in hair that feels brittle or falls out in large quantities.
Shared triggers: alopecia areata and traction
Beyond pattern loss, both sexes can be affected by:
- Alopecia areata: an autoimmune condition where the immune system attacks hair follicles, causing circular bald patches.
- Traction alopecia: mechanical loss caused by constant tension from tight hairstyles, which can permanently damage the follicle over time.
- Telogen effluvium: a stress-induced condition where physical or psychological trauma pushes hairs prematurely into the shedding phase.
When to seek clinical advice
- Sudden, patchy loss: may indicate alopecia areata — consider a dermatology consult.
- A burning or itching scalp: may signal inflammation or infection — a scalp analysis is sensible.
- Fatigue alongside hair loss: may point to thyroid or nutritional issues — a blood panel can help.
"Hair loss is a medical symptom, not just a cosmetic concern. By diagnosing the specific biological triggers early, we can often halt progression and stimulate significant regrowth."
— Pharmacist: Kulsum Rajani
The expert takeaway
If you are looking to understand your hair loss properly, don't rely on general information alone. Speak with a clinical professional who can look at the whole picture and design a plan tailored to your unique biology. Early intervention is the single most important factor in successful hair restoration.