Early warning signs and symptoms Initial signs and symptoms of diabetic hypoglycemia include: 
Looking pale (pallor)
Shakiness
Dizziness or lightheadedness
Sweating
Hunger or nausea
An irregular or fast heartbeat
Difficulty concentrating
Feeling weak and having no energy (fatigue)
Irritability or anxiety
Headache
Tingling or numbness of the lips, tongue or cheek
 Nighttime signs and symptoms If diabetic hypoglycemia occurs when you're sleeping, signs and symptoms that may disturb your sleep include: 
Damp sheets or nightclothes due to perspiration
Nightmares
Tiredness, irritability or confusion upon waking
 Severe signs and symptoms If diabetic hypoglycemia isn't treated, signs and symptoms of hypoglycemia worsen and can include: 
Confusion, unusual behavior or both, such as the inability to complete routine tasks
Loss of coordination
Difficulty speaking or slurred speech
Blurry or tunnel vision
Inability to eat or drink
Muscle weakness
Drowsiness
 Severe hypoglycemia may cause: 
Convulsions or seizures
Unconsciousness
Death, rarely
 Symptoms can differ from person to person or from episode to episode. Some people don't have any noticeable symptoms. It's also possible you won't have any symptoms of hypoglycemia. It's important to monitor your blood sugar levels regularly and keep track of how you're feeling when your blood sugar is low.