Mr Clegg, who represented the Hallam constituency in Sheffield between 2005 and May 2017, spoke out about his son's health scare while appearing on ITV’s Lorraine show this morning.
The former Lib Dem leader and his wife, Miriam Gonzalez Durantez, revealed that their eldest son Antonio, now 15, was diagnosed with Hodgkin lymphoma last year, after finding a small, painless lump in his neck.
An ultrasound scan and biopsy revealed stage 2 lymphoma, and Antonio was treated with four monthly cycles of chemotherapy, a course of steroids, and a cocktail of medication.
He is now in remission.
The couple, speaking ahead of tonight’s launch of a major report by blood cancer research charity Bloodwise, said that their first reaction to their son’s diagnosis was an 'overwhelming wish' to take the cancer away from Antonio and take it on themselves.
Miriam said telling their son he had cancer was one of the 'toughest things' their family has faced.
She said: "We dealt with it by carrying on and trying to keep things as close to the routine that we had beforehand and also being very open.
"The day that he was told, and I think that probably us telling him is one of the toughest things that we have ever done, the following day he went to school, he stood up and he told everybody 'I have cancer'.
"That's the way he dealt with it but other children and other families deal with it in a different way, you have to find your way."
Mr Clegg said: "His lymphoma was all over his chest and his neck and he gets tested every three months, I think for a couple of years, so there is always a slight spike of anxiety with us every three months but basically he is on the road to recovery.
"Interestingly the thing he was most concerned about was sort of falling behind his classmates. His anxiety was more about keeping up with his classmates, keeping up at school. So it was very impressive actually."
He added the couple's other children, Alberto and Miguel, had taken the news well.
"Once they heard from us that he will be OK, again they are just so, so practical - just 'OK then'," he said.
The couple are raising awareness of the charity Bloodwise, which will launch a report tonight urging more research into less toxic treatments for children with cancer.
Miriam said: "With chemotherapy they poison your body so that you can get cured and it's a shock to see it happen.
"We do realise how incredibly lucky we are both with the fact that the treatment has worked and how well he seems."
In their written preface to the report, they say that Antonio was taking up to 20 tablets per day, and that his treatment resulted in complete hair loss, vomiting and extreme fatigue.
Dr Alasdair Rankin, director of research at Bloodwise, said: “The reality is that one in five children diagnosed with the most common type of leukaemia still do not survive, and that those who do often experience devastating side effects both during and after treatment. This is simply not good enough.
"We need to save every child’s life, make the treatment process much kinder and give them the life they would have had without cancer.
"Only by funding more research into better treatments will we be able to finish the job that has been started and give children the best possible cancer treatment.”