Spina Bifida Occulta
I was born with spina bifida occulta, a minor form of spina bifida that hasn't affected my spine much, but my urinary tract. As a child, I got very frequent infections of the urinary tract and as an adult, I am more susceptible to them than most.
One time, the infection spread to my kidneys, which was a lot more serious. I had to go into the hospital for several days.
I have a friend who has the more serious form of spina bifida and is confined to a wheelchair.