Why may insulin coma occur?

A coma can occure when our bodies dont make enough insulin or make to much when it makes too much our bodies slowly begin to shut down because our BSL is too ,low and one of the first and most major functions that losses ability to respond properly is our brains this happens because our brains cant function well without the right balanced amount of sugar, hence the reasons for forgetfulness and headaches when our BSL is low,this also has a lot to do with our nerves.