But the plucky pupil is determined to live a full life... and even plans to be a doctor when she grows up.
Katie, from Springburn, was the first in her family to be born with neurofibromatosis, a group of conditions causing lumps to grow on nerves.
She has spent months of her life in hospital and deals every day with the results of her complex medical conditions.
But, instead of letting her illness get the better of her, Katie uses her hospital experiences to help other children.
And she is fighting to catch up on the school work she has missed while being in hospital.
Her mum, Angela, said: "Katie was six before she was diagnosed with neurofibromatosis and it was an illness we had never heard of before.
"It is a genetic condition but no one in our family has it, Katie is the first.
"She has been ill ever since she was small and once one thing is fixed there is always something else and then something else.
"But she is fantastic the way she copes. Over the years I have shed more tears than her."
Angela, who has four older children, says she bled throughout her pregnancy with Katie and was sure there was something wrong.
When Katie was born, Angela had Strep B - a condition that can be fatal in babies - and the newborn was taken to the special care baby unit in the Southern General.
Katie had problems with her kidneys and with her lungs and doctors tested her for cystic fibrosis but the results were negative.
She also developed scoliosis, curvature of the spine.
Finally, when Katie was six, a doctor in A&E noticed she had cafe au lait spots on her skin - brown coffee-coloured skin patches like a birthmark - and wrote to her GP to suggest she may have neurofibromatosis.
Angela, 50, said: "I had never heard of it before. I worked as a medical auxiliary in Stobhill at the time and I had been asking every doctor I came across about Katie's symptoms to see if they had any idea of a diagnosis.
"It was purely by chance we found out what was wrong but it means that in the future she could grow tumours around her body."
Despite the diagnosis, her health issues continued to become worse.
Problems with Katie's lower back led to her having an MRI scan which showed a symptomatic syrinx - a rare, fluid-filled cavity in her spinal cord that causes terrible pain.
In March 2011, Katie was taken to Yorkhill Hospital to have a shunt put in her brain to deal with her encephalitis, or water on the brain.
The operation was not a success and had to be repeated.
Meanwhile, she had developed appendicitis but, because of her high pain threshold, she didn't complain and doctors nearly missed the condition.
In total, Katie had four shunts put into her brain and 11 operations.
Her condition deteriorated to such an extent she ended up on life support and in intensive care. It was June before she was ready to leave hospital.
Angela said: "That was a truly terrible time. We went into hospital in March and were still there four months later."
But it was during this time that Angela learned of how special her daughter was to other patients.
She added: "I could give you a pile of cards that came in for Katie when she was ill. They just flooded in.
"Katie had been on a ward with children who had brain tumours and were dying but these parents took the time to send cards and the messages inside touched me so much.
"I had no idea what an impact Katie had been making on other children on the ward."
THE family, which includes dad Robert, 55, and Katie's big brother, three big sisters and niece, receives support from the charity Confer.
It is now launching a new charity called Funny Lumps to help children with neurofibromatosis and their families.
Angela said: "Karen from the charity came out to the house and I couldn't believe what I heard. She was just a wealth of knowledge and a complete life line.
"The charity has been great by organising days out for the kids and letting Katie meet other children who are like her.
"I feel as if with Katie you have always got a fight on your hands for treatment but Karen has been such a support."
Due to her illness Katie missed a lot of primary school but she is now in first year at Springburn Academy - and determined to make up for lost time.
The pupil is determined to excel in her school work.
And she plans to study medicine after school.
Angela said: "Katie was really clever at primary school but missed a lot of classes.
"Now she's in first year Springburn Academy is being really, really good with her - they couldn't give her more support.
"And she is determined that she wants to be a neurosurgeon - a paedeatric neurosurgeon, in fact.
Angela added: "Katie tries to do things that she maybe shouldn't be doing. She will be agony but it is her choice what she feels capable of doing - she's got to make her choices.
"She has such a good spirit and I hope that is what keeps her going."
l Funny Lumps launches at The Riverside Museum tomorrow at 11am.