A boy was given a shock diagnosis after being told to visit the doctor when he stopped playing with his friends.
Cian McGrath was just six when a family friend noticed he was not joining in with pals and suggested a visit to the GP.
The youngster also started to feel more tired than usual and had bruises appear "out of nowhere" towards the end of the school year.
Doctors confirmed that Cian's symptoms were because he was suffering from leukaemia, the most common cancer in young children.
His family were shocked by the diagnosis which led to years of gruelling treatment and surgery, reports the Liverpool Echo.
Cian, now 22, told the publication: "I remember when I was six, I wasn't myself.
"It was near the end of Year Two and close to the last days of school and one of my mum's friends, who was a doctor, noticed that I was tired a lot and not playing with my friends.
"Then bruises started coming out of nowhere and eventually I was diagnosed."
Cian recalled how he spent his early childhood "in and out" of Alder Hey children's hospital in Liverpool and underwent regular operations.
"I remember I used to go to theatre once every four to six weeks and it was quite a lot," he continued.
"But when I was ten, I was in remission."
Cian is now studying medicine at university and has been inspired to give back to those who helped him.
His placement at the oncology department of Newcastle Hospital really hit home and spurred him on to make a difference.
Determined to raise money for Children's Cancer North, the student will take part in the Great North Run next month.
The charity aims to support families of children with cancer, raise awareness and invest in research.
Cian Said: "I've recently done a placement on the oncology department in Newcastle and it was there I was really able to see the work being done by doctors.
"It felt right to be able to do something and raise some money for the charity.
"It's more than helping through treatment. There are specialists who help you play games and make you feel somewhat normal.
"It just feels great to be able to raise money and make you feel like you are making a difference, no matter how much you raise.
"You can see it at the hospital, you can see the work everyone does to try and help and it feels nice to see the charity is making a difference on the wards they are at, and knowing that I was one of those children."
Cian has so far raised £825 of his £1,500 goal, according to his gofundme page.
The student said there is a huge range of symptoms for leukaemia which can present itself in many different ways.
According to the NHS, there are four main types of leukaemia which are named according to the type of white blood cells affected.
The first is chronic myeloid leukaemia, with main symptoms including tiredness, weight loss, loss of appetite, abdominal discomfort, and bleeding or bruising easily.
Acute myeloid leukaemia is another main type, with main symptoms including looking pale, tiredness, breathlessness, unusual bleeding and more infections than usual.
Chronic lymphocytic leukaemia presents symptoms such as fatigue, frequent infections, enlarged lymph nodes, bruising and bleeding easily, weight loss and severe night sweats.
While acute lymphoblastic leukaemia comes with the main symptoms of feeling tired or unwell, aching joints and bones, common infections and unusual bleeding and bruising.
