There is a moment of silence before the sound of drumsticks clicking together four times and the guitar begins its intro.

Talia Dean stands smiling in front of an ivy-draped microphone in a purple dress and leather jacket and launches into Get Up - a pop-rock track produced by Queen guitarist Brian May, which took her band, Kings Daughters, to number 12 in the charts last year.

Since her appearance on X Factor in 2017, where judges described her voice as "beautiful" and "amazing", Talia has been ever more in the public eye, but she has been hiding something.

"I just wanted to keep up this facade of nobody knowing, but I don't think I can do it much longer," she says. "I should own it now."

Talia, 35, from west London, has axial spondyloarthritis (axial SpA), a form of inflammatory arthritis that affects the spine and other joints and ligaments in the pelvis. Back pain and stiffness, fatigue, weight loss and night sweats are among the symptoms.

In five years, it's predicted, Talia won't be able to walk unaided. But if she had received appropriate treatment earlier, she says, she'd be dancing for years to come.

It all started with a pain in her hip..

Talia was 18 and studying music, acting and dancing at West Thames College, where Freddie Mercury had studied 40 years before her (when it was Isleworth Polytechnic).

"I just put it down to growing pains or something. I didn't really know what it was, but it was relentless and I really walked funny with it.

"We would always sit on the floor and do stretches and it was just painful. I couldn't really stretch my legs out and I just thought, 'What have I done?'

"It went on for weeks, to the point where I ended up going to A and E and just saying, 'I can't walk, it really hurts.' So at 18 years old, I'm on crutches and no-one can really find why."

The pain became so unbearable she had to leave the course.

A couple of years later, it went away and for a while she was fine. Then it returned, when she was 22 or 23, as a pain in her lower back.

Although she was still singing, she had also started to train and work as a hairdresser and wondered whether the problem stemmed from being on her feet all day.

"You just make all these excuses, you know the whole world has a back ache, so I didn't really think anything of it."

To begin with she just took painkillers, but it soon became clear she would need medical help. Over the next six years she had four MRIs and numerous X-rays. She saw rheumatologists and urologists, as well as osteopaths and acupuncturists.

And all the time, her symptoms were getting worse. It got to the point that she couldn't turn over in bed, and getting up in the morning would push her to tears.

Axial SpA symptoms

*  Symptoms include gradual onset of back pain and stiffness, early morning stiffness that wears off during the day with exercise, weight loss, fatigue, and night sweats

* They often start in the late teens or early 20s, an age when "no-one is thinking it could be arthritis," says Dr Dale Webb of NASS

*  Often patients have flare-ups, when symptoms temporarily intensify

*  In severe cases, vertebrae in the spine fuse together, resulting in a loss of mobility and curving of the spine (kyphosis)

*  Associated conditions include uveitis (inflammation of the uvea, or middle layer of the eye), psoriasis and bowel problems

"It was like someone had stabbed me. It was horrible and it never really went away. I just always had a backache and I always felt tired."

At 29, 11 years after her first symptoms, she had a "complete breakdown", she says.

"I thought, 'There's something wrong with me, I'm dying and they can't find it,'" she says.

She developed a fear of doctors and blood tests, and decided she would prefer not to know what was wrong with her. When she became pregnant her symptoms abated, but they returned again after the birth. This time the pain was in the middle of her back.

"I was looking in the mirror and I thought, 'I don't look right,'" Talia says.

"I noticed that I was kind of wonky, and being a dancer and being on stage, I always had a great posture."

Talia says she even struggled to lift her son out of the cot.

"I felt like an 80-year-old woman, and I looked like an 80-year-old woman," she says. "I looked frail. I was holding myself like an old lady, so I was tilting forward."

She noticed that she couldn't wiggle her hips or twerk. She describes it as feeling like "someone had glued a rod to me".

But then something happened that persuaded Talia to have one further MRI scan.

"I was lifting my son out of the bath and my back gave way and I dropped him in the bath. I fell forward and smashed all my face on the taps," she says.

"It was horrible. I had black eyes. I was really injured. That was when they said to me, 'We really need to look at your spine, you shouldn't be struggling to carry a baby out of a bath.'"

It was on her 34th birthday last year that the results came through - showing that vertebrae in her spine had fused together.

Axial SpA is a form of arthritis, but unlike the more common osteoarthritis, which generally affects people in middle age or older, it often strikes early - 24 years is the average age of onset.

"Axial SpA is not the kind of wear and tear that you get in osteoarthritis," says Dr Dale Webb, CEO of the charity the National Axial Spondyloarthritis Society (NASS).

"Nor is it the mechanical back pain if you lift an object incorrectly or you do some sports. This is about inflammation caused by a particular inflammatory response in the immune system.

"What happens is your symptoms will come on very slowly - over months - and it could be pain in the lower back or in the joints at the base of the pelvis."

Dr Lesley Kay, a consultant rheumatologist at the Freeman Hospital in Newcastle, says this pain often wakes people in the second half of the night, and they may be very stiff when they wake up in the morning.

"It tends to be better as they move around during the day, and worse again in the evening," she says.

Another result is that someone with the condition "may feel generally unwell or disproportionately fatigued".

When inflammation subsides, new bone can develop as part of the body's healing process, and vertebrae can fuse together - a process called ankylosis - leading to loss of mobility.

"Axial SpA" is an umbrella term, covering ankylosing spondylitis - Talia's condition, where changes to the spine or bones of the pelvis can be picked up in an X-ray - and cases where inflammation can only be detected by MRI. Someone may also have the symptoms without any visible inflammation.

"My ankylosis is so severe even the doctors said they hadn't seen a case like mine in a really long time and I would be lucky if I didn't need full assistance by the time I'm 40 in my mobility," says Talia.

"It was so preventable, it is so preventable, and it took over 15 years."

Talia thinks one reason her condition wasn't detected sooner is that it is often thought of as a male disease.

"This in part goes back to the days when we used to diagnose only with an X-ray," says Dr Webb of NASS. "For reasons that aren't completely understood at the moment, if you look at the percentage of people who've got ankylosing spondylitis - they've got the bony formation and the joint damage - two-thirds are men and one-third is women."

As a result, many GPs would say, "It's a man's disease, women don't get it," Dr Webb says.

"Now actually when you look at the MRI scans - the people who haven't got the bony formation - there, two-thirds are women and one-third is men. In other words, women get the same inflammation, the same disease, but don't often go on to get the same structural damage in their joints that men do."

According to Dr Webb, it takes on average 6.5 years for men to receive a diagnosis and 8.8 years for women.

A recent study suggests that although X-rays generally show less structural damage to women's joints than men's, the "disease burden" of axial SpA can be more serious for women.

"These are often the things that it is very difficult to measure, such as fatigue and pain which can contribute very significantly to disability and disease impact, and also contributes to the stigma of invisible disability," says Dr Kay.

Women are also more likely to have "atypical symptoms", she adds, including pain in the middle of the back - as Talia did after her pregnancy - rather than the lower spine and pelvis.

"This means that a non-specialist may not join the dots so easily to think of the diagnosis and organise the right tests."

Talia would like to raise awareness of the fact women also get the condition.

"Had they have known what they were looking for, or even given me a chance to think, 'Actually women can get this, so it is possible,' that would have saved my life as a dancer," she says.

"I walk around and people think I'm drunk. I'm not drunk, I just can't walk, it's just so painful."

She would like anyone who has recurring back problems to be tested for the condition.

"This is what gets me," she says. "I could forgive everybody that missed my diagnosis. I could forgive them if it was a rare condition that's hard to find, but it isn't and I'm really, really angry about it because the more I research it, the more I think, 'Wow, every time it was staring you in the face.'"

Axial SpA facts and treatment

*  It's estimated that one in 200 adults in the UK have axial SpA, according to NASS

*  Over 85% of people who have axial SpA test positive for a gene called HLA B27 - one of a number of genes thought to play a role in the development of the condition

*  Environmental factors are also thought to play a part, including the microbiome within the gut

*  Treatments include exercise, physiotherapy, hydrotherapy and medication - and biologic therapy which aims to stop the immune system damaging joints

*  The earlier the diagnosis the better the outcome - "my case is a particularly bad case and I don't want to scare people into thinking that everybody's going to end up in a wheelchair," says Talia

One thing that is crucial with axial SpA is exercise to improve and maintain flexibility, posture and strength. Talia says her condition was made worse because she wasn't given the right advice.

"You know what they say, the doctors, 'Rest, rest, rest. Here's some painkillers, lie in bed until the pain goes away.' I should have been up, moving, stretching, yoga," she says.

Dr Kay says "the right kind and amount" of exercise, guided by a physiotherapist is the "core treatment" for axial SpA.

"It's hard for patients to appreciate this at first," she says.

"It seems counterintuitive that someone with pain, feeling tired and unwell should exercise more and that it will help.

"I have seen in a lot of patients' eyes when I introduce this that they question whether I really appreciate how bad they feel. However, when people have really taken this on, they come back to clinic and describe a great deal of improvement, particularly in stiffness and in sleep quality."

Talia says she had become used to hiding her condition, before the pandemic put a halt to live performance.

"We always work out what's a good angle, whether it's photos or a music video or an interview. You'll find I'm always the one sitting in the middle, because I have to be supported on both sides. There's certain tricks that we've learnt with me," she says.

She started to wear a jacket to cover her shoulders and neck, and sometimes she changed her set by putting a ballad in the middle, so that she could sit down.

"I don't wear those massive heels that I used to wear - little changes just help so much."

The impossibility of performing during the pandemic, has led her to begin work on a new podcast, in which she will speak to unconventional social media influencers. She has also started her own online music academy, where people can learn to sing or play an instrument.

This is a new source of joy.

"I can teach this from home sitting down, and was nominated for a best new business award," she says.

And thanks to the fact that she has now been properly diagnosed, Talia is due this year to start biologic therapy, which blocks aspects of the immune system in order to slow down its attack on the spine.

She is determined to get back on stage when the pandemic is over, but she will no longer be hiding her condition.