The personal statement is also a great place to explain more serious problems, like less_than_ideal grades or test scores. Don't be afraid to write something like, "I don't test well" in the statement. As long as you can provide a good reason for you app's problems, it's okay to address them directly. You won't be able to hide it from admissions officers anyway, so providing a reason for problems is always preferable to ignoring them.
"The prospect of helping people has driven me to fulfil many goals in life and this is truly my dream. Although it is great to have ambitions _ I now want to translate my goals into reality. Becoming a nurse is a natural extension of my interest in medicine. Following graduation, I found myself advising investment bankers on the stock exchange, secretly desiring the opportunity of helping others overcome illness and promote health."