Jo Hooper spent her 20s trying to climb the career ladder, quickly rising through the ranks with promotions and pay rises.

"I loved being good at it," said Jo, a former communications professional.

But just after Jo landed her dream role at 30, she struggled with burnout and had to take time off work.

Burnout is recognised by the World Health Organization as a state of physical and emotional exhaustion.

Recent statistics show 22 million working days were lost in Britain because of work-related stress in 2024-25.

Jo, now 39 and based in Penarth in the Vale of Glamorgan, said: "I wanted to be a head of communications by the time I was 30, which I did by doing all things you'd expect, working long hours, saying yes to everything including mad things like taking my boss's kids to school."

"I genuinely thought these were all good opportunities, and I was going to grab them with both hands," said Jo.

"I remember being in the bathroom crying, hyperventilating, but I never thought this isn't sustainable, never thought I can't do this any more.

"I just thought I needed to change job and I'd be fine. I thought the fix was being in a different organisation but the way I behaved, what I thought was expected of me, was the same everywhere."

Jo hit burnout a year into her management role, and it led to two breakdowns within a year.

"I definitely think it was a case of being forced to stop by my body and my mind," she said.

"I found it really difficult to make decisions, like my brain was working slower. I remember feeling like someone had flipped a switch and my brain had just broken."

The charity Mental Health UK reports that two in five young workers aged 18 to 24 took time off due to poor mental health caused by stress in 2025.

However, there have been concerns raised about how people are signed off work.

Earlier this year, hundreds of GPs told the BBC they had never refused to sign a patient off work for mental health issues.

Olympic athlete Laviai Nielsen recently told the BBC she realised she had burnout too late, after the 2024 Paris Olympics, while Green Party MP Carla Denyer announced in May she would be taking a leave of absence due to burnout.

Dr Jill Williams, a psychologist and business coach in north Wales, specialises in working with people affected by burnout.

She said: "It's actually perfectionists or those who go the extra mile who are more likely to experience this.

"The same traits that get you promoted will be the same ones that burn you out, unfortunately."

Public Health Wales' Amy Davies said the phrase burnout could be used interchangeably for stress, but said the two were different things.

"Stress can feel like drowning, but burnout can feel like having nothing left to swim with," she said.

Both experts have helped BBC News bust burnout myths and misconceptions.

"It's not necessarily just work, we can see it an awful lot in carers and students, any situation where there is long-term stress," said Williams.

As it is caused by prolonged, unmanaged stress, it can stem from any persistent, demanding role or responsibility.

Burnout and depression are distinct conditions, and the World Health Organization does not consider burnout to be a mental health condition or illness.

"If burnout experiences are unaddressed it may lead to those conditions developing," said Davies.

"Sometimes it can be helpful, but it also needs to come with changes to the context that's causing the distress," said Davies.

"For many people rest is necessary, but it's not always enough. If you go back to work and your attitude to work is the same, then you're going to have the same result, so something needs to change," added Williams.

Jo ended up leaving her career after she realised it was not sustainable. She was diagnosed with anxiety and depression.

"I've learnt the hard way that rest doesn't fix burnout, and it certainly didn't fix the breakdown for me. Actually changing the things that burnt you out or broke you down is the only way to get over it.

"Now I'm a woman on a mission to convince others to work less, because I spent 10 years not doing that, and it nearly broke me."

Jo does public speaking and coaching to support business owners and employers to help others avoid reaching burnout.

"I'm in control, I run my business, I get to decide how it works, I get to decide what I do and who I work with and that's a huge part of the process for me," she said.

"I detest this optimisation culture of trying to be as productive as possible. Feeling like we constantly have to optimise ourselves and productivity is just forcing us into working more and living less... I think it just needs to get in the bin."

Some workforces have raised concerns about staff members leaving jobs due to burnout, including midwifery and teaching.

Hannah Leonard, from the Royal College of Midwives union, said: "Midwives do an extraordinary job, and they deserve to feel pride in their profession, not burnt out within a few years of qualifying".

Neil Butler from the teaching union NASUWT said: "Changes must be made to bring back the joy into teaching. Whilst it is a relentless grind we will continue to lose good teachers from classrooms in Wales."

Laura Doel from Trade Union Congress Cymru, said: "Our research shows that stress is the number one risk at work, higher than traditional dangers like exposure to chemicals, working at height and unsafe machinery."

She said actions by employers who offer wellbeing measures are welcomed, but tackling the root cause of stress such as "low pay, insecure contract and impossible workloads" is key.

A spokesperson for the Health and Safety Executive (HSE), Britain's national regulator for workplace health and safety, said: "Employers have a legal duty to protect workers from risk factors that cause work-related stress by assessing and properly managing key areas of the work."

If you or someone you know has been affected by the issues raised in this story, information about available help and support can be found via BBC Action Line.