Diabetes can be explained simply: It occurs when your body can no longer control blood sugar levels. But the impact of diabetes, well, that can be more complicated. Elevated blood sugar can cause damage to large (macro) and small (micro) blood vessels and trigger widespread problems throughout many systems and organs in the body. The good news is that diabetes-related complications are not inevitable. Keeping blood sugar at near-normal levels can prevent and control them effectively. In fact, reducing your A1C (a measure of your average blood sugar level over a three- or four-month period) from 8 percent to 7 percent can slash your risk of some complications by as much as 70 percent. Here’s a look at the most common diabetes complications and what you can do to avoid them.