Olsen Sagers, two, first started suffering from ‘constant tonsillitis’ and a fever in March 2025
A little boy was left so weak he couldn’t walk after “constant tonsillitis” turned out to be a rare disease. Olsen Sagers began having “constant” tonsillitis and a fever in March this year. His family GP prescribed him around eight courses of tonsillitis antibiotics, but by July, his symptoms left him unable to walk, leaving his parents “scared and confused”.
His mum Rebecca Jennings, 26, pushed for a blood test and they were referred to Worcestershire Hospital on July 9. A day later, Olsen was diagnosed with Acute Lymphoblastic Leukaemia – a rare cancer that affects the blood and bone marrow. On July 12, Olsen started chemotherapy at Birmingham Children’s Hospital with his first course lasting four weeks.
Rebecca, a pub supervisor from Kidderminster, Worcester, said: “His fever and tonsillitis symptoms just wouldn’t go away. It was so scary and confusing when he started struggling to walk. We just wanted to get to the bottom it to help him.
“Getting the diagnosis was earth-shattering. Obviously, my mother’s instinct knew something was wrong, but I never in a million years thought it would be leukaemia. But Olsen’s been so brave and I’m blown away with everything he’s enduring.”
After initially noticing Olsen’s persistent cough and elevated temperature in March 2025, which GPs attributed to tonsillitis, his condition deteriorated significantly by July. With little Olsen unable to walk, mum Rebecca demanded blood tests from the GP and the duo were quickly referred to Worcestershire Hospital.
On July 10, Olsen received a diagnosis of Acute Lymphoblastic Leukaemia – an uncommon blood cancer predominantly affecting children and young people, particularly those aged four and under. Just two days later, the courageous youngster began his initial chemotherapy treatment via an IV line in his chest alongside steroids. Every few weeks, Olsen must undergo a general anaesthetic for a lumbar puncture procedure, allowing chemotherapy to be administered directly into his spine.
Rebecca said: “It’s been really horrible because there’s nothing you can do to take it away. Physically he’s been exhausted and it’s really taken it out of him.”
Olsen has now been fitted with a feeding tube after completely losing his appetite due to the treatment. Medical professionals have informed Rebecca there’s a 90 per cent likelihood that Olsen will achieve complete remission, though chemotherapy and additional targeted therapies are expected to continue for up to three years.
Rebecca has since resigned from her role as a pub supervisor to look after Olsen, adding further financial pressure on the family. Olsen’s grandad, David Warren, 67, has established a GoFundMe page to provide support for Olsen and raise funds for The Children of Worcester and Herefordshire Cancer Fund. Both David and his son, Michael Warren, 29, will be undertaking a 25km run from Bristol to Bath on 27 September.
Rebecca said: “The response has been incredible, and it means the world.”
To contribute, visit the GoFundMe page.