Kerry has been visiting the doctors with the condition since her early teens but nobody can actually say what causes the swelling.
Kerry explains: "I've been asked several times when I'm due to give birth, and I usually have to explain that my "baby" is a roast dinner".
"If I go out for a meal, I always have to wear something loose, because I know I'll probably expand. In the end, I had to buy a pair of maternity jeans with an elasticated waistband, because they were the only thing I could be comfortable in." she said.
Now this really is Strange People!