Her doctor thought it was a calcium deficiency, but it was really brain cancer.

Sleepless nights, a loss of sensation and the niggling feeling that something wasn’t right.

A Sydney journalist has revealed how her brain cancer was misdiagnosed as a calcium deficiency.

Boel Eriksson, 31, shared her story with news.com.au in a touching first person piece that revealed the horror behind her ordeal.

It may have started with insomnia but Eriksson was soon rendered unable to perform such simple tasks as typing at her desk, carrying her handbag and even applying mascara.

The 31-year-old visited her doctor multiple times and received solutions for each symptom – sleeping pills for the insomnia, antidepressants for her depression – but was given no hint of a larger more menacing issue.

On her third visit, her desperation forced her to use his own pen to demonstrate the severity of her condition.

"I even grabbed my GP’s pen to demonstrate how my right hand struggled to grab it, and how I couldn’t use the pen to write with," she said.

The doctor allegedly said the loss of sensation was to do with a calcium deficiency and referred her for a blood test as well as a psychologist's appointment.

"I’ll never forget the look on the doctor’s face when he pointed to the big, black blob on my brain, describing the 'growth' as 'very concerning'," she said.

"I was in shock, but at the same time I was relieved - I wasn’t just imagining things!"

Eriksson was rushed into surgery the next day where 90 per cent of the "growth" was removed and sent away for testing.

The remainder was said to be so dangerous that removing it could have rendered her paralysed.

Today marks the start of brain cancer awareness month so I got the cat beanie on that my bestie Anna gave me #curebraincancer #beaniesforbraincancer

A photo posted by Boel Eriksson (@boel84) on May 1, 2016 at 3:19am PDT

Eriksson left the hospital believing the worst was over but was soon called back to discuss her results.

The 31-year-old was told it was a Glioblastoma Multiforme - a deadly brain tumour that rarely offers patients positive results. 

"He explained that I have Glioblastoma Multiforme stage 4, the biggest cancer killer in people under 40. I'll be 32 in June," she said.

Eriksson was once again rushed into surgery to remove the final ten per cent.

The operation was a success but recovery saw her pushed to her limit as she underwent six weeks of radiotherapy, and chemotherapy for an indefinite period.

The journalist watched as close friends and strangers alike flocked to offer their support.

"They say I’m brave. I don’t feel brave. I’m only doing what you would have done if you were in my shoes," she said.

Eriksson is now eating organically, taking Chinese herbs, receiving acupuncture and avoiding sugar. She hopes this strategy will take to the five-year-post-cancer mark and far beyond.

Feature image via instagram: @boel84

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