It paralyses every inch of her being and, on those days, she can be found curled on the recliner in the kitchen sobbing for relief.
After living with a congenital heart disease for 29 years, Isabel is immune to painkillers.
The acute pain is caused by the pressure put on her body by her failing heart. The resulting need for a heart transplant means she is hooked up to an oxygen tank 24 hours a day.
The former beauty therapist from Bishopstown in Cork can’t walk more than 100 metres unaided and has to take at least 16 tablets every day. She lives with regular dizziness and a constant throbbing pain in her chest and legs because of the pressure on her circulatory system.
She is one of 21 people on the official waiting list for a heart transplant from the Mater Hospital in Dublin.
In 2003, 18 heart transplants took place. This year, the number of transplants dropped to five due to a sharp drop in donations.
Isabel, one of six children, was offered a heart transplant assessment at the end of last year. It was decided that without a transplant, she was unlikely to survive another two years.
“This sounds strange but I can live with the pain. I just want to be able to get out of the house again as that has really been out of the question for the past three or four months,” she said. “I just want to get dressed up, meet my friends, have a laugh, have a bop and not worry about that bleeper.”
Like every potential transplant patient, Isabel can’t leave the room without her pager. It is the means by which the Mater Hospital will contact her to let her know they have located a suitable heart.
The decision to have a transplant didn’t come easily as she has already had three major operations - the first when she was just three weeks old.
“If I get a flu or an infection next week, I could be dead the following week. My resistance is that low,” she said.
This year she invited 200 friends and family to a huge pink-themed party at a local bar - she doesn’t know if she’ll be alive to celebrate her 30th.
“I just want to urge people to donate. I know it’s a really hard thing to do when someone is dying but it means a life for me. All I want is to be able to work again, get married and have kids. I want to be an ordinary person, that’s all,” she said.