Tasha Jilka, 19, thought her tears were being caused by an allergy to eye make-up.
But after seeing her GP, she was diagnosed with a rare cancer called olfactory neuroblastoma – which meant there was a tumour at the back of her nose.
"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," said Tasha, who is backing the Teenage Cancer Trust's efforts to raise awareness of the disease.
"It was put down to a cold and the weather and I was told it would go by itself. I went back a few times when it didn't get better and was referred to an optician, but they couldn't find anything either."
Tasha, from Rushey Mead, Leicester, was just 16 when her symptoms began in May 2008. Over the next four months, her eye got worse so she was referred to hospital. She had an operation to clear a blocked tear duct, but her symptoms persisted, so she was referred to specialists.
"I had a similar eye test but this time doctors also looked up my nose and could see a lump," said Tasha. The lump proved to be cancerous and in May 2010 Tasha underwent surgery to remove it.
But it was so severe that surgeons had to reconstruct her nose and she is still having problems with the vision in one eye. She has had two major operations, one to remove the tumour and a second to rebuild her nose.
Brave Tasha said: "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.
"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."
• For more information about teenage cancer, go to www.teenagecancertrust.org