Why am I losing my hair?

28 MARCH, 2022

As we saw last night at the Oscars, hair loss is a very emotional subject and not one to be joked about. 

Hair loss (alopecia) is a broad term resulting from several different causes.

pulling hair out of a brush

Below is a brief run through of how normal hair grows along and an explanation of different types of hair loss. Take a look also at ‘hair the inside story’ on this site  for further information about the science behind hair. 

Humans are usually born with approximately 5 million hair follicles, with no new follicles thought to be added after birth. Hair goes through 3 phases, anagen or growing phase, catagen or transition phase  and telogen or resting phase ( 85-90% of hair on your head is in the growing phase at any given time). When you move from the growing to resting phase the follicle sheds it’s hair. It is normal to shed up to 50- 100 stands of hair a day. The longer the growing phase the longer your hair (provided you don’t cut it of course), the growing phase in some people can be up to 6 years.* The resting phase lasts between 2-3 months. After the resting phase the follicle then starts regrowing new hair so kick starting the cycle again. 

Hair loss can cause scarring of the scalp (cicatricial) or it can be  non scarring (non cicatricial).

Non scarring hair loss has numerous causes the commonest being genetically determined male or female patterned hair loss. Men can start loosing hair from the crown and temple area while women notice thinning where they tend to part their hair and hair line. Most people affected by genetic hair loss first see signs of thinning aged 40 onwards, but some hair loss can start in late teens and early 20s which can be particularly distressing. 

Other causes of reversible non scarring hair loss in both males and females include, stress, autoimmune diseases, tinea capitis (ring worm)  radiation and cancer chemotherapy treatments, some medications, illnesses such as anaemia, thyroid disease or acute infections (including Covid), hormonal changes such as having just had a baby, prolonged tension on the hair due to hair styles (for example pony tails), and a nervous condition causing the person to pull the hair out by the roots.

The scarring (non reversible) types of hair loss can be caused by amongst other things injury, infection and inflammation. 

Finally we all suffer from seasonal hair loss with our hair being thinner in the summer than winter. Most people barely notice this but to some it is quite obvious.

Hair is part of our identity, is is something we have grown up with and hair loss, even genetically determined hair loss in male or females can be a very emotional experience. 

Apart from genetically determined male or female patterned hair loss, most non scarring hair loss grows back with rest, good food and a healthy body. There are treatments to help genetically determined male or female patterned hair loss to grow back which you can discuss with your doctor.   Our article on ‘all about hair’ also gives you tips about looking after your scalp. 

But for those whose hair does not grow back - as we saw at the Oscars, it is no laughing matter. 


*(Wolff et al. 2009; Habif 2010)


Written by Dr Tina Grayson

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