She thought her left eye was becoming watery because it was either reacting to her make-up or the odd weather.

As the eye problem kept getting worse, 19-year-old Tasha Jilka from Leicester saw a doctor, expecting a remedy to some kind of allergy. She later learned a cancer tumour has grown behind her nose, which meant she needed surgery to remove the life-threatening foreign growth.

It took a year after Tasha noticed the symptom in her left eye before Tasha was diagnosed to have a rare case of olfactory neuroblastoma. She was 16 years old at the time.

Her nose was disfigured as a result of the cancer, as her doctors had to reconstruct virtually her entire face after the surgery. Even the shape of her face has changed, Daily Mail noted.

Tasha did not immediately learn her condition as doctors and opticians she consulted had missed the growth due to its odd location.

"My left eye was very watery but I just put it down to make-up. It kept getting worse and I decided to go to my GP. It was put down to a cold and the weather and I was told it would go by itself," she told Daily Mail.

She said she had gone back to the same GP a few times until she was referred to an optician, who also failed to point out the real problem.

As her eye condition continued to get worse, Tasha was later referred to a hospital in Cambridgeshire, quite near her family home at the time.

Tasha's new doctors thought her problem was isolated to her eye, and suspected unblocking a tear duct would put an end to the inexplicable welling up, but she did not get better after an eye operation.

When Tasha's family moved to Leicester in 2009, she went to see her GP again, and this time she was referred to specialists at Leicester Royal Infirmary.

"I had a similar eye test but this time doctors also looked up my nose and could see a lump," Tasha recalled.

It was in Leicester where doctors took a biopsy of the lump found at the back of her nose, and subsequently diagnosed the cancer.

Two years since she first noticed her left eye welling up, Tasha had surgery to remove the tumour.

Even after having the tumour removed and her nose reconstructed, Tasha is still having problems with her vision in one eye.

Looking back, Tasha said she has been strong through her ordeal, but she feels things could not have been so bad if doctors had spotted her tumour from the start.

"I feel if I had been diagnosed earlier and known more about the symptoms, I might not have had to have two such major operations. I have lost a lot of feeling in my face and my sense of smell," she said.

Tasha is now supporting a campaign by charity the Teenage Cancer Trust to raise awareness of cancer among young people, sharing with her audience her plight and how she motivated herself to carry on after a life-changing condition.

In one of her interviews, Tasha said: "I hope that by explaining what happened to me - where my symptoms were persistent and unexplained - it will help raise awareness of how important it is for doctors and people to be aware of cancer. It took a long time for me to be diagnosed so I hope my story will help others."