The common symptoms are listed, but will vary from person to person. The early warning signs of a reaction are due to the release of a hormone called adrenaline. It is also called the excitatory hormone or epinephrine. Most people make it when they are excited or scared. It causes shakiness, sweating, dilated pupils, a rapid heart rate, and other symptoms.
Some people tend to have only mild reactions and can easily detect symptoms.
This seems to be more common in the first few years after diagnosis. Others may have more difficulty detecting symptoms. This seems to happen to people who have had diabetes longer or whose blood sugars tend to run at more normal levels. Sometimes this is due to less adrenaline being available. The greater fall is more likely to cause adrenaline release and symptoms.