Hypoglycemia or low blood glucose level happens when the blood glucose falls below a range of 50 – 60 mg/dL (normal range: 70 – 110 mg/dL). It can occur as a result of various reasons: too much insulin or oral hypoglycemic agents, too much physical activity, or too low consumption of food. It has no specific time in happening, but may occur before meals especially when meals or snacks are consumed late in the day.


The signs and symptoms present in hypoglycemia are commonly classified into two: central nervous system (CNS) manifestations and adrenergic manifestations.

In mild hypoglycemia, whenever the blood sugar level drops, it stimulates the brain to release epinephrine and norepinephrine, which both serve as a hormone and a neurotransmitter. The release of these neurotransmitters result in the discharge of glucose from the body’s reserved energy stores.

The decline of blood glucose levels in moderate hypoglycemia robs the brain cells of energy that is needed for it to properly function well. Severe hypoglycemia, on the contrary, involves the CNS function being so damaged that a diabetic individual cannot treat hypoglycemia by themselves and will definitely need the assistance of another person.

Adrenergic manifestations

  • Sweating, warm feeling
  • Tremors
  • Tachycardia (accelerated pulse rate)
  • Palpitations
  • Nervousness, anxiety
  • Hunger
  • Pallor, cold and clammy feeling
  • Mydriasis (dilated pupils)
  • Numbness (paresthesias — tingling and pricking sensations felt on the skin)

CNS manifestations

  • Inability to concentrate, impaired judgment
  • Headache
  • Lightheadedness, fatigue, weakness
  • Confusion
  • Memory lapses
  • Numbness of the lips and tongue
  • Slurred speech, difficulty talking
  • Impaired coordination, sometimes described as being in a “drunken state”
  • Emotional changes, moodiness, depression, exaggerated concerns
  • Irrational behavior, combative, irritability
  • Diplopia or double vision, blurred vision
  • Drowsiness
  • Abnormal breathing
  • Disoriented behavior
  • Seizures, generalized or focal
  • Difficulty arousing from sleep
  • Loss of consciousness

(*italized symptoms are manifestations seen when severe hypoglycemia is evident.*)

Causes of Hypoglycemia

If a person has diabetes, insulin abnormality is always present, either because their pancreas is not producing any or not enough insulin (type 1 DM) or because their receptor cells are not responding normally to it (type 2 DM).

This results to having high levels of glucose freely flowing in the blood stream. To correct this, diabetics self-administer insulin or oral hypoglycemic agents in order to lower blood sugar to normal levels.

Problems may arise when too much insulin is present in the bloodstream. For example, hypoglycemia happening in the middle of the day happens when the morning dosage of insulin reaches its peak action. Hypoglycemia that happens during the late afternoons also corresponds with the peak activity of the insulin given during that morning. On t