Neuroglycopenic Manifestations of hypoglycemia symptoms
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, sleep
Confusion, amnesia, dizziness, delirium
Staring, "glassy" look, blurred vision, double vision
Automatic behavior
Difficulty speaking, slurred speech
Ataxia, incoordination, 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 age and by the severity of the hypoglycemia. In young children vomiting often accompanies morning hypoglycemia with ketosis. 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 newborns, hypoglycemia can produce irritability, jitters, myoclonic jerks, cyanosis, respiratory distress, apneic episodes, sweating, hypothermia, somnolence, hypotonia, refusal to feed, and seizures or "spells". Hypoglycemia can resemble asphyxia, hypocalcemia, sepsis, or heart failure.
In both young and old patients, the brain may habituate to low glucose levels, with a reduction of noticeable symptoms despite neuroglycopenic impairment. In insulin-dependent diabetic patients this phenomenon is termed hypoglycemia unawareness and is a significant clinical problem when improved glycemic control is attempted. Another aspect of this phenomenon occurs in type I glycogenosis, when chronic hypoglycemia before diagnosis may be better tolerated than acute hypoglycemia after treatment is underway.
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.