The former Liberty X singer is currently deciding whether to undergo a double mastectomy and have her ovaries removed after discovering that she has the BRCA2 gene, meaning she has an 80% chance of contracting cancer.
"I know I shouldn't read the trolls that comment on my news articles in the media, but I do. For some reason I thought there may be some kind of pillow of support or advice from those going through similar things," she tweeted.
"Instead it's a whole heap of abuse from people who are clearly uneducated and downright nasty. To clear a few of your deluded comments - yes I have 80% chance of breast cancer - I'm not exaggerating.
"Myself and Hugh will never ever break up. He is my rock and my life will have no meaning without him."
Heaton continued: "I did not deliberately show my patch on my care sheet from the hospital - I must not apply pressure from clothing garments or alike to the patch for 10 days!
"I did not sell my story #fact. And yes I am in a fortunate position where what stories I tell get out into the press. Raising awareness on this is not a scare tactic.
"It's simply showing people if they have a family history of this it's important to get checked. And finally no, I do not have private health, I pay my taxes like everyone else, so I use #nhs all the way and couldn't be happier."
Heaton, who was rushed to hospital last week due to a long-term heart problem, went on to thank those who have offered advice and support as she makes the difficult decision.