What're the damaging effects of hypoglycemia?

Varies: True hypoglycemia can cause mental confusion, coma and death. If you suspect you have hypoglycemia see a doctor and be tested.

High insulin: Very common cause of hypoglycemia is high Insulin levels (almost always related to excess sugar and carb intake). Initially the high Insulin causes a reactive hypoglycemia, however over time, the chronically high Insulin levels lead to "insulin resistance". When your Insulin no longer works your blood sugars will rise and you develop diabetes. This is 100% preventable wi proper diet.