What is a Rule Out
Say you go to a doctor because your ankle hurts. You took a pretty bad fall and twisted it. We’d make some basic assumptions from the clue of trauma and twisting motion to rule in sprain, strain, fracture (compound, compressed, or spiral), and periosteal bruising. These would be high on the rule out list. But let’s say we asked some more questions and found out that you were 80 years old, arthritic, haven’t taken care of yourself and cancer runs in your family.