I drove a friend to an appointment at his cardiologist's office a few weeks ago While we were waiting I noticed an elderly gentleman sitting across from me. He didn't look well, and he was talking on his cellphone. "I don't know what's going on," he said. "I'm sweating all over." After he hung up and I approached him and asked if he needed some help. He replied that he thought he needed some sugar. He didn't have a glucometer, but the woman next to him did, so I did a quick blood test for sugar. He had a reading of 50, well below the normal range of 80 to 120. I notified the front desk and they brought two glucose wafers. "I already tried that," the man said, "and it didn't help." He ate the wafers anyway. At that point the medical staff the arrived. I told them he was very diaphoretic (sweaty), and they put him in a wheel chair and took him to an inner room.
At first glance, the man's statement that he needed sugar plus a reading of 50 would lead one to a conclusion that he was simply having a hypoglycemic emergency, i.e. low blood sugar. I'm sure this was true, but that was just the beginning. Look at all the facts: we were in a cardiologist's office, he was an elderly male, he didn't look good, and especially, he was intensely sweaty all over, a classic symptom of what? A heart attack! Remember that older people, and also women don't necessarily present with a lot of chest pain.
The point of this story is, don't get cocky or even overconfident when you find something wrong with the victim. You always have to do a complete assessment, including a SAMPLE history, to find everything that is wrong with her or him.