I feel compelled to put this in as I had no idea an uncomfortable plaster cast could be so dangerous.
Almost everyday after I had surgery to reconstruct the wrist end of my radius, I had discomfort with my 'back slab. A back slab is a half cast wrapped with bandage, so that when the swelling from the initial injury and surgery subsides, it can be re-wrapped/ tightened if necessary. The disadvantages are that there can be more movement, which can shuffle the ends of the break together and slow healing.
My back slab was uncomfortable from day one, and I re-wrapped it almost everyday, until I got some fat padding from the chemist. It was like heaven to not be so uncomfortable. But there were sore spots on three bony protrusions - the ulna wrist knuckle, a small bony point nearby in my hand, and the end of the radius, at the base of the thumb. The pain from the pressure nearly drove me crazy, and I finally got to my cast with the pliers to make space. This relieved it somewhat, but now 7 weeks into my injury and a week and a half out of my cast, these areas are still very sore, and one is quite swollen.
Until this morning, I had found nothing referring to this problem, apart from my physio talking about inflammation from the cast. Googling today, I came up with this page: http://www.primary-surgery.org/ps/vol2/html/sect0335.html
which talks about the dangers of having pressure sores/ not enough space, and they are huge! Gangrene and deformities are not to be taken lightly, and it can set in overnight.
So, if your cast doesn't feel right, do something about it......................