• Abnormal mentation, impaired judgement
• Nonspecific dysphoria, anxiety, moodiness, depression, crying, fear of dying
• Negativism, irritability, belligerence, combativeness, rage
• Personality change, emotional lability
• Fatigue, weakness, apathy, lethargy, daydreaming, excessive sleep
• Confusion, amnesia, dizziness, delirium
• Staring, “glassy” look, blurred vision, double vision
• Automatic behavior
• Difficulty speaking, slurred speech
• Ataxia, in-coordination, sometimes mistaken for drunkenness
• Focal or general motor deficit, paralysis, hemiparesis
• Paresthesias, headache
• Stupor, coma, abnormal breathing
• Generalized or focal seizures

Not all of the above manifestations occur in every case of hypoglycemia. There is no consistent order to the appearance of the symptoms. Specific manifestations vary by the age and by the severity of the hypoglycemia. In older children and adults, moderately severe hypoglycemia can resemble mania, mental illness, drug intoxication, or drunkenness. In the elderly, hypoglycemia can produce focal stroke-like effects or a hard-to-define malaise. The symptoms of a single person do tend to be similar from episode to episode.

In the large majority of cases, hypoglycemia severe enough to cause seizures or unconsciousness can be reversed without obvious harm to the brain. Cases of death or permanent neurologic damage occurring with a single episode have usually involved prolonged, untreated unconsciousness, interference with breathing, severe concurrent disease, or some other type of vulnerability. Nevertheless, brain damage or death has occasionally resulted from severe hypoglycemia (e.g., Sunny von Bülow).