One of the more distressing problems in diabetes is hypoglycemia unawareness. Normally, a person will feel warning symptoms when their blood sugar goes low, such as shaking and sweating caused by release of stress hormones. However, those with hypoglycemia unawareness have reduced warning signals and do not recognize they are low. Even if they happen to do a blood sugar test they may not realize what they need to do to treat the low. Luckily, stress hormone release is usually adequate to eventually raise the glucose level, although this may take several hours to work.

http://www.diabetesnet.com/diabetes_control_tips/hypoglycemi...