Possible causes
- Androgenetic alopecia – an inherited sensitivity of hair follicles to the hormone DHT; in men receding temples and crown, in women thinning on top.
- Telogen effluvium – 2–3 months after stress, illness, childbirth or rapid weight loss, much more hair falls out at once.
- Iron deficiency – low ferritin is a common cause, especially in women.
- Thyroid – both an underactive and an overactive thyroid can weaken hair.
- Hormones – stopping contraception, polycystic ovary syndrome, perimenopause.
- Lack of protein and nutrients – when intake is restricted, hair is a low priority for the body.
What to check
- Ferritin, iron and blood count – the basic tests for hair loss.
- TSH and anti-TPO antibodies – to assess the thyroid.
- Vitamin D and zinc – deficiency is linked to poorer hair quality.
- For women, testosterone, DHEA-S and SHBG – if you also have acne, an irregular cycle or increased body hair.
What helps
- Enough protein – at every meal; hair is made of keratin.
- Correct deficiencies – supplement iron, vitamin D or zinc in a targeted way based on results.
- Gentle care – less heat, fewer tight hairstyles and harsh treatments.
- Stress management and sleep – in telogen effluvium hair usually recovers once the trigger has passed.
- See a dermatologist early – effective treatment exists for hereditary thinning and works best when started early.
When to see a doctor
See a dermatologist if hair falls out in patches, your scalp is red, itchy or scaly, if the shedding lasts more than six months, or if it comes with fatigue, an irregular cycle, acne or excessive body hair.