A brain tumour patient gained 10 stone and saw his feet swell three sizes following treatment for the disease.
Jay Cramb from Glasgow said his weight soared from 15 to 25 stone and he now takes a size 15 shoe after being diagnosed with a tumour above the pituitary gland, which controls the body's hormones.
The sports massage therapist, 42, spoke out about the changes to his body to raise awareness of brain tumours, said to be the biggest cancer killer of people under 40.
Mr Cramb, a keen rock climber, was told he had a craniopharyngioma tumour in 2015 and has since undergone surgery and radiotherapy.
He said: "I have to take a mountain of medicines, which have resulted in me adding half my body weight and my feet increasing to a size 15, making it difficult to find shoes that fit.
"I regularly have endocrine appointments to try to get the dosage levels right and I have to admit that although I am normally a gregarious and very positive person, I do have some quiet, dark moments now and again.
"However, I love my job working as a sports and remedial massage therapist - I've always enjoyed keeping fit myself and am a great fan of rock climbing."
He added: "I was shocked to discover that brain tumours are the biggest cancer killer of children and adults under 40 yet just 1% of the national spend on cancer research has been allocated to this devastating disease."
Mr Cramb, who runs Ridgestone Physical in Glasgow city centre, is offering treatments worth £1,440 as part of a prize draw to raise funds for Brain Tumour Research.
Joe Woollcott, fundraising manager at the charity in Scotland, said: "Jay's story reminds us that brain tumours are indiscriminate - they can affect anyone at any age.
"What's more, less than 20% of those diagnosed with a brain tumour survive beyond five years compared with an average of 50% across all cancers, and we cannot allow this desperate situation to continue."
To enter the prize draw, make a donation to Brain Tumour Research via www.justgiving.com/fundraising/RidgestonePhysical-PrizeDraw and email your address and contact details to email@example.com