It must have seemed the cruellest of blows. After years battling to overcome ill health and triumphing to win her dream job, TV and radio presenter Jameela Jamil was given shocking news.

“The doctor said ‘you have a lump on your breast’. Hearing those words was a reminder, a kick up the bum if you like, telling me that life is very unpredictable,” says the 29-year-old wryly as she recalls the moment in December she feared she had cancer.

“Three women in my family, close relatives, have had breast cancer, and two have died from it, and still I never thought it could happen to me. I didn’t even regularly check my breasts.

“With the arrogance of youth I thought ‘I don’t drink, don’t smoke, I don’t do drugs, so why would I get cancer?’ The week I spent waiting for the result of the biopsy to see if it was malignant felt like the longest of my life.”

With an ability to overcome adversity seemingly imprinted in her DNA – she was born partially deaf, suffers from coeliac disease and several food allergies, and was housebound for a year following a car accident in her teens – this recent setback is the one that has proved a life changer for the stunningly beautiful and outwardly resilient Jamil.

Within days of learning to her relief that the tumour was not malignant (she had a lumpectomy on both breasts), she quit as first female solo presenter of the BBC Radio One Chart Show, the coveted role she’d performed since 2012. This year, she’s travelled anonymously avoiding the spotlight, and funded herself through writing.

“That scare shocked me to the core, that’s for certain, but I felt so lucky to be alive. So I certainly don’t feel sorry for myself,” she says.

“It might seem a psychotic, insane thing quitting a job after I’d built a great career over eight years, but it was a wake-up call. All too often we ignore those, forget that we don’t know how long we’re here for and that we need to make the most of every moment. I knew it was right to make time for myself to have adventures and fulfil dreams,” declares the former model scout who found overnight fame in 2009 when she was plucked from obscurity to co-host Channel Four’s T4 youth show with Nick Grimshaw.

That career success at 22 – and a glamorous life interviewing a host of celebrities – was unimaginable during a childhood and teenage years blighted by ill health.

Born partially deaf, and with a tendency to labyrinthitis which affects balance, she’d had a string of ear operations by the time she was 13. She has 70% audibility in one ear and only 50% in the other.

“Worse for me were allergies to shellfish and peanuts, which often meant I’d end up in hospital as any contact with those would make my windpipe swell up,” she recalls.

By the age of 12, after a history of digestive problems, she was also diagnosed with coeliac disease, an autoimmune condition where the body reacts to gluten.

“I was a kid and totally underestimated its impact and thought ‘well, it won’t kill me like my reaction to prawns or peanuts might’ so I carried on eating cakes and fast food which just made things worse. Also at that time, there was hardly any food suitable for those with allergies and intolerance. So I felt constantly tired and low,” says Jamil.

Her digestive problems were temporarily overshadowed at 17, when in a road accident she broke several bones including her hip and severely damaged her spine. But by the age of 21, her health had reached a crisis point.

“After the accident I was confined to the house for a year, used a wheelchair for a year and had to learn to walk again using a Zimmer frame. I got through all that, which I’m really proud of, but as the time went on, it became obvious that my gut was in a terrible state,” she says.

“I just started to get sicker and sicker. My face started to swell up when I ate – it ballooned and not just when I ate gluten – and I started passing out.

“I had no energy and relied on endless cups of coffee and sachets of sugar to keep me going. I lost 20lbs in weight and got worryingly thin.

“I seemed to be allergic to everything, including fruit and vegetables, and could only stomach chicken and chips. It felt as though I had a continual hangover, and I suffered nauseous and couldn’t concentrate.”

Inadequate dental treatment, she believes, had compounded her problems.

“Blood tests finally revealed I had high levels of mercury in my blood and I think the only source could have been silver amalgam teeth fillings which were done really badly, leaked and later weren’t removed properly. The mercury literally poisoned me and burnt holes in my digestive system,” she says.

It’s taken six years to fully recover, but she now appears the picture of health. “I haven’t been sick for two years now and I’ve never felt better,” she beams.

“I’m always optimistic although there was a time years ago when I did think ‘what’s happened to my life’? I couldn’t imagine how things would ever work out.

“But one of the advantages of going through some of the things I have is that, after surviving them, nothing scares you really. It puts everything into perspective and gives you confidence.”