Ownership of a bike and a pair of Crocs set 23-year-old Hamish McLaren on a path from membership of a grassroots cycling club to achieving a National ranking in road and track cycling. A promising start to a dream career in an elite sport.
“I was absolutely captivated by cycling,” Hamish recalls. “I set out on a mission to become as good as I possibly could at riding a bike.”
Increase in infections
Despite early success, things started to change for Hamish at around age 15. He began suffering from repeated infections, unexplained fatigue and a noticeable drop in performance.
“I had post-viral fatigue that lasted for months. I kept training, week in and week out, but no matter what I did, I couldn’t get better.
“As an athlete, you’re taught to ignore your excuses and push through the pain. But I was constantly getting ill and no one – including me – understood why.”
Years of missed signs
Hamish tried everything to improve his health: from buying multivitamins to overhauling his lifestyle. He changed his bedding, used an air purifier, adopted strict routines and avoided alcohol and allergens. Yet his health continued to decline.
“Each year, the illnesses got worse – chest infections, respiratory tract infections, even parasites and skin infections. Nevertheless, somehow, I was still managing some of my best power numbers on the bike.”
What Hamish didn’t yet know was that he was living with an undiagnosed primary immunodeficiency: common variable immunodeficiency (CVID).
Taking control of the diagnostic journey
In 2023, prompted by a friend’s experience, Hamish took out private health insurance. It was a decision that would prove critical.
“I had no idea how important that decision would be. After one race in Spain left me bedbound again, I started using every resource I could to find out the underlying cause of my illnesses.”
He began booking private blood tests and consulting various specialists. Eventually, a low lymphocyte count led one endocrinologist to refer Hamish to a haematologist, who then made a referral to immunology.
“I didn’t want to accept ‘maybe this is just how you are’ as an answer. That’s when I booked an appointment with an immunologist in Manchester. I walked in with 15 pages of test results.”
The diagnosis that changed everything
Finally, in early 2024, Hamish was diagnosed with CVID. It was a moment of validation, clarity and relief after years of confusion.
“It was the thing that had been holding me back for the past eight years, and now it finally had a name.”
CVID, a disorder that affects the body’s ability to produce antibodies, explained the chronic infections and fatigue. And while the diagnosis came as a shock, it also marked a turning point.
A new chapter, powered by plasma
Thanks to his diagnosis, Hamish was able to begin immunoglobulin therapy, a life-changing treatment made possible by plasma donations from the public.
“Growing up, I took pride in my health. I never thought I’d be dependent on something like this. But I’m incredibly grateful for every single donor who makes my treatment possible.”
The experience has inspired Hamish to share his story publicly and advocate for awareness and plasma donation. His YouTube channel documents his journey as an athlete with CVID.
“I wanted to give people a story they could relate to – especially people, like me, who were fit and healthy for most of their life and then hit a wall. If just one person sees my story and recognises the signs in themselves, then it’s worth it.”
Discovering Immunodeficiency UK
One crucial part of Hamish’s journey was finding Immunodeficiency UK.
“Their resources helped me understand what tests to ask for and what treatment options were available. Their guidance on plasma-derived treatments, particularly immunoglobulin therapy, gave me hope that I could finally begin to manage my condition effectively.”
Hamish now looks to the future with renewed purpose. While he continues training and navigating life with CVID, he’s committed to raising awareness of the condition so others can be diagnosed earlier and receive the treatment they need.
“Thanks to an early diagnosis and the right treatment, I can finally look ahead with confidence. But I know many others aren’t so lucky. That’s why I’m sharing my story.”
Posted June 2025
