The presenter was diagnosed with prolactinoma, a non-cancerous tumour, eight years ago during a check-up while filming television show The Supersizers about diets throughout history.
She went online to assure people she is alright, tweeting: “Ta for sweet tweets about my prolactinoma. It’s benign & non-symptomatic.
"All fine, Let’s focus on those less fortunate in the world.”
The 45-year-old, who hosts the hit baking show alongside long-time friend Mel Giedroyc, said living with the condition can be a challenge.
“Sometimes it’s big and makes me mad, and sometimes it’s small and is in the background,” she told Good Housekeeping magazine.
“Sometimes it screws up my hormones.”
Perkins said being told she would not be able to have children was difficult: “I don’t know if I would have gone on to have children.
"But as soon as someone says you can’t have something, you want it more than anything.”
She said Giedroyc giving birth to her first child made her acutely aware she will not experience motherhood.