Common presenting symptoms include nausea, confusion, tremor, sweating, palpitations, or hunger. Patients may present with a non-specific clinical history.
Documentation of a blood glucose <3.3 mmol/L (<60 mg/dL) with accompanying symptoms is crucial to diagnosing clinically significant hypoglycaemia.
Important causes to consider are iatrogenic or factitious hypoglycaemia secondary to insulin or sulfonylurea use. Another common cause may be physiological reactive hypoglycaemia. However, the most worrisome causes are insulinoma and tumour-related hypoglycemia.
Preferred treatment for an insulinoma is surgical excision.
Hypoglycaemia is a clinical syndrome present when the blood glucose concentration falls below the normal fasting glucose range, generally <3.3 mmol/L (<60 mg/dL). When glucose values drop below the normal fasting range, glucose meters are not accurate and laboratory serum or plasma testing is useful to confirm the actual blood sugar value. Whipple's triad should be present in cases of true hypoglycaemia: hypoglycaemic symptoms, accompanying low blood glucose concentration, and resolution of symptoms after raising the blood glucose concentration to normal.
This topic covers non-diabetic hypoglycaemia in adults.
History and exam
Key diagnostic factors
- generalised tingling
- blurred vision
Other diagnostic factors
- unexplained weight gain
- unexplained weight loss
- short stature
- middle age
- female sex
- ethanol consumption
- bariatric surgery
- liver failure
- renal failure
- intense exercise
- adrenal insufficiency
- growth hormone deficiency
- glycogen storage diseases
- anorexia nervosa
- exogenous insulin
- ackee fruit ingestion
- haloperidol exposure
- quinine exposure
- fluoroquinolone exposure
- sulfonylurea exposure
- disopyramide exposure
- beta-adrenergic-blocking agent exposure
- salicylate exposure
- tramadol exposure
- proton pump inhibitor exposure
1st investigations to order
- serum glucose
- liver function testing
- renal function testing
- serum insulin
- serum C-peptide
- serum beta-hydroxybutyrate
- serum sulfonylurea
- thyroid-stimulating hormone levels
- serum cortisol
Investigations to consider
- 48- to 72-hour fast under observation
- oral glucose tolerance test
- serum insulin-like growth factor (IGF)-II
- serum adrenocorticotropic hormone
- serum human growth factor (HGH)
- insulin suppression test
- serum proinsulin
- CT scan abdomen and pelvis with and without intravenous contrast
- transabdominal ultrasound
- endoscopic ultrasound
- nuclear imaging with octreotide scan
exposure/overdose medication, toxin, ethanol
bariatric surgery, anorexia, malnutrition, ackee fruit ingestion
renal failure, liver failure, sepsis, or other endocrinopathy
Udaya Kabadi, MD
Professor of Medicine
University of Iowa
Des Moines Internal Medicine Residency Training Program
Veterans Affairs Medical Center
UK is an author of a number of references cited in this topic.
Professor Udaya Kabadi would like to gratefully acknowledge Dr Steven Kunkel, a previous contributor to this topic.
SK declares that he has no competing interests.
David J. Leehey, MD
Renal and Hypertension
Professor of Medicine
Division of Nephrology
Department of Medicine
Loyola University School of Medicine and Edward Hines Jr VA Medical Center
DJL declares that he has no competing interests.
Shehzad Basaria, MD
Johns Hopkins University School of Medicine
SB declares that he has no competing interests.
David Hopkins, FRCP
Clinical Director/Clinical Lead for Diabetic Medicine
King’s College Hospital NHS Foundation Trust
DH declares that he has no competing interests.
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