A staggering 840,000 women in the UK suffer from the hair pulling disorder trichotillomania (TTM), according to hair-loss specialist Lucinda Ellery.

[Read more: Pulling your own hair out: What it feels like to live with Trichotillomania]

The average sufferer starts pulling their hair around the time of puberty, and the condition is considered to be connected with those who are highly intelligent, sensitive and working in high-powered or pressurised jobs.

Trichotillomania: What is it?

TTM is a neurobiological condition that causes overwhelming urges to pull out your own hair and often serves as a mechanism for dealing with stress and anxiety.

TTM is a rarely discussed impulsive disorder, despite the fact it is more common than bulimia and can take many forms including eyelash pulling, skin picking and nail biting.

Lucinda, who for the past 30 years has been pioneering hair loss solutions for sufferers, describes TTM as something that’s used for ‘self-calming’. Many women, she says, are sometimes not even aware that they are pulling.

The condition can easily escalate, leading to extensive emotional and social consequences for the individual. Some women will pull out so much of their hair it leaves bald patches the size of their fists or more; Lucinda explains that a whole head of hair can be extracted within five hours.

TTM – why 840,000 British women are pulling their hair out

TTM affects around eight times as many women as men and estimates suggest that 2% of the world’s population may at some time suffer from this condition. Incredibly, only 10% of women sufferers will seek treatment for it.

Lucinda, who runs hair extensions and hair loss management studios in London, Manchester, Edinburgh, Bristol and Los Angeles, said her clients share their experiences of TTM with her.

“Everyday my clients tell me their heartfelt stories so I understand how difficult and often humiliating it can be to lose your hair through TTM or for other reasons,” she says.

“The fact thousands of women in the UK are fighting the urge to pull out their hair is staggering.

[Read more: 'I was addicted to pulling out my grey hairs']

“Too many women are suffering in silence and I hope that through educating people about TTM during International No Pulling Week (October 1-7), we’ll be able to help many more women become ‘pull‐free’ and in control, so they no longer have to deal with TTM in secret.”

One sufferer, who has had the condition since the age of 24, commented: “You could always tell if I have had a stressful or bad day because patches of hair loss, the size of 50 pence coins, would become visible again."

Sam Faiers and US actress Olivia Munn have both admitted to suffering from TTM as they pull at their eyelashes.

Dr Sarah Brewer, GP, said: “Despite the fact TTM affects up to 1 in 25 people at some point in their lives, many people are still not aware of the condition which is why International No Pulling Week is so important. It is time we had a more open discussion about TTM and what we can do for those suffering secretly and alone with this condition.”