Sometimes we get aches and pains that others are convinced are not real. Sometimes they're right and the symptoms are only in our heads. But, a lot of the time, these aches and pains are often a sign that something is really wrong with our bodies, and thanks to our diligence, we're able to make our way to an understanding doctor.

But what happens when even the doctors who you trust to keep you alive don't believe you?

Katie Blake is a graphic designer living in England. A decade ago, she started to have certain concerning symptoms and went to the hospital. Over a period of 10 years, Katie went to several doctors. Her symptoms varied, from stomach pain to bloating and extreme tiredness.

But, despite the persistence of these complaints, she was consistently dismissed and made to feel as though she was wasting the doctors' time. "I had all this pain and extreme tiredness but they kept putting it down to irritable bowel syndrome and me," she says, "I had been driving back from my work falling asleep at the wheel."

Living with these symptoms for so long without anyone believing you affects a person's mental health. Katie fell into a deep depression and started to drink and avoid people. "I thought everyone felt like me, but they just sucked it up and carried on."

Then, she was sent to the hospital for tests on an infected gallbladder. When doctors received her results, it proved that Katie hadn't been making up tales after all.

She had colon cancer. And even worse, in the time it went untreated, the tumor had grown to the size of a potato. It was strangling her colon and had grown so large that it risked perforation, which could kill Katie immediately.

Despite the life-threatening nature of her tumor, Katie says her first feeling was relief at being believed. She had to undergo a six-hour operation to remove the tumor. She also had to go through multiple rounds of chemotherapy to remove a second tumor they found on her liver.

Katie is warning people about her colon cancer symptoms. She says doctors did not immediately diagnose her because she did not have a change in her bowel movements, which is usually a tell-tale symptom.

On her blog she writes, "Cancer shouldn't be found by accident. People know their bodies. People should be listened to."