Several. You start to feel weak, fatigued , confused, you have trouble concentrating and when really low you sweat, your tongue gets thickand others might think you are drunk as your balance would be off too. The last step is passing out.
Recognize and abort . Initally, irritability, blurred vision.Tremors, pallor, irregular or rapid forceful heartbeat, hunger with cravings for sugar, confusion. And if unrecognized, progression to , sense of loss of control, combativeness, inability to walk, stupor and finally deepening coma. If related to too much Insulin it is critical to abort the progression by taking in glucose orally.