People who have chronic medical conditions often wear a medical I.D. bracelet in case of emergency. Diabetics might want to do that too. In this week's Dealing with Diabetes report, Eye on Health spoke with a local nurse who has seen far too many diabetics in the emergency room.

In the emergency room at Valley Hospital, diabetes program director Diane Harman sees the end result of damage caused by diabetes -- including heart attack and stroke. But while a catastrophic event is apparent, out-of-control blood sugar levels can go completely unnoticed.

"And that's probably one of the scary parts is that people can be a-symptomatic to it. And so they can walk around with blood sugars that are 3, 4 times higher than normal and have no symptoms related to it," said Harmon.

Warning signs of diabetes can be unexplained increases in thirst, urination, and breathing. But without faithfully monitoring blood sugar levels, it's hard to know for sure.

"And I think with diabetes, you have to trust when we tell you that even though these high blood sugars are causing you damage, you may feel perfectly fine," she said.

Harman says one of the biggest challenges for her patients is getting enough exercise.

"Some people are really easy. They'll go to the gym, they'll do what needs to be done. For other people, I take a smaller step. Would you park in the back of a parking lot and walk into the grocery store. Would you take a flight of stairs vs using the elevator. So try to give them ideas so they can fit daily activity in on a regular basis," she said.

Exercise is so important to managing diabetes or avoiding it altogether -- that Harman calls it "invisible insulin."