Causes and Management of Hypoglycaemia

Definition of Hypoglycaemia:

When blood glucose level is below 3.5 mmol/ L then it is called hypoglycaemia. It occurs in a patient who is treated by insulin or sulphonylurea & not a manifestation of the disease itself.

Fig: Hypoglycaemia

Causes of Hypoglycemia:

It includes-

  • Missed, delayed or inadequate meal,
  • Unexpected or unusual exercise,
  • Alcohol,
  • Errors in oral hypoglycemic agent or insulin dose/schedule/administration,
  • Poorly designed insulin regimen, particularly if predisposing to nocturnal hyperinsulinaemia,
  • Lipohypertrophy at injection sites causing variable insulin absorption,
  • Gastroparesis due to autonomic neuropathy,
  • Mal-absorption, eg. celiac disease,
  • Unrecognized other endocrine disorder, eg. Addison’s disease,
  • Factitious (deliberately induced),
  • Breastfeeding by diabetic mother.

Management of Hypoglycaemia:

Clinical features:

  • Usually rapid onset,
  • May be preceded by odd behavior (eg. aggression),
  • Sweating, increase pulse, seizures.

Common symptoms of hypoglycemia:


  • Sweating,
  • V Trembling,
  • Pounding heart,
  • Hunger,
  • Anxiety.


  • Confusion,
  • Drowsiness,
  • Speech difficulty.

Inability to concentrate, Incoordination


  • Nausea,
  • Headache,
  • Tiredness


  • Blood glucose: very low
  • Urine examination: No glycosuria, no ketonuria

Treatment of Hypoglycemia:

  • Give 50 ml 50% dextrose IV state. This harms veins, so follow by 0.9% saline flush. Expect prompt recovery.
  • If not recovered, give dexamethasone 4 mg/4hour IV to combat cerebral oedema after prolonged hypoglycemia.
  • A continuous IV infusion of dextrose (5% or 10%) may be necessary to prevent recurrent of hypoglycemia.
  • If IV access fails try glucagon 1-2 mg.
  • On regaining consciousness give sugary drinks.

Risk Factors of Severe Hypoglycemia:

It includes the following:

  • Strict glycaemic control,
  • Impaired awareness of hypoglycemia,
  • Age (very young and elderly),
  • Increasing duration of diabetes,
  • Sleep,
  • C-peptide negativity,
  • History of previous hypoglycemia,
  • Renal impairment,
  • Angiotensin converting enzyme (ACE) genotype.

Difference Between Hypoglycemic Coma and Hyperglycemic Coma:

Point of Differences

Hypoglycemic Coma

Hyperglycemic Coma


Missed meal, delayed meal

Excessive exercise

Insulin overdose


Low dose of drug,

Digestive disturbance,

Stressful condition,

Intercurrnet infection.


In minutes

Over hours or days


Vomiting (occasionally)

Abdominal pain and vomiting


Normal hydration most skin and tongue,

Marked sweating,

Breathing shallow or normal,

Pulse full,

Systolic BP normal or raised,

Brisk reflexes, Babinski +ve.

Dehydrated — dry skin and tongnue,

Sweating absent,

Deep rapid breathing/Kussmaul breathing,

Pulse weak,


Diminished reflexes.


No ketonuria

Ketonuria, glycosuria


Hypoglycemia, normal plasma HCO3

No hyperkitonaemia

Hypoglycemia, reduced plasma HCO3


IV glucose

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