The Short Guide to Hypoglycemia
Hypoglycemia: the whole thing in five minutes, for when you want the numbers and nothing else.
Blood glucose falling too low, usually in people taking insulin or sulfonylureas.
Key takeaways
- Commonly defined as: below 70 mg/dL
- Early symptoms: shakiness, sweating, hunger, anxiety, fast heartbeat
- Most useful single change: Carry fast-acting carbohydrate, such as glucose tablets or juice, at all times.
- Commonest mistake: Driving when your glucose is low or you feel any symptoms.
- See a doctor if any of the signs under "When to speak to a doctor" below apply to you.
The numbers, in one place
| Measure | Figure |
|---|---|
| Commonly defined as | below 70 mg/dL |
| Early symptoms | shakiness, sweating, hunger, anxiety, fast heartbeat |
| Immediate treatment | 15 g of fast-acting carbohydrate (the 15-15 rule) |
| Recheck after | 15 minutes, and repeat if still below 70 mg/dL |
| Severe low | glucagon, given by someone else, if the person cannot swallow safely |
In one paragraph
It can develop quickly, impairs judgment exactly when judgment is needed, and is dangerous while driving.
Worth doing
- Carry fast-acting carbohydrate, such as glucose tablets or juice, at all times
- Check your glucose before driving and regularly on long drives
- Follow up with a snack or meal once your glucose is back in range
- Ask about a glucagon prescription and show the people around you how to use it
Worth avoiding
- Driving when your glucose is low or you feel any symptoms
- Treating with chocolate or cookies, whose fat slows the rise
- Ignoring repeated episodes rather than reviewing treatment
Related topics
- What the Guidance Really Says About Medicines and Driving (Medicines Safety)
- Gestational Diabetes: Sorting the Evidence From the Noise (Pregnancy and Postpartum)
- Acute Kidney Injury: What the Evidence Actually Says (Kidney Health)
- What the Guidance Really Says About Sick Day Rules (Long-Term Conditions)
Where to go next
- Popular Beliefs About Hypoglycemia, and What Is Actually Published
- Starting Out With Hypoglycemia
- Hypoglycemia — the reference entry
- Diabetes: The Complete Guide
- Diabetic Eye Screening: Sorting the Evidence From the Noise
- Carbohydrates and Blood Glucose: Sorting the Evidence From the Noise
When to speak to a doctor
Call 911 if someone with diabetes becomes unconscious, has a seizure, or cannot swallow safely — give glucagon if it is available, but do not put food or drink in their mouth. See your doctor about repeated episodes, loss of the early warning symptoms, or episodes overnight.
Where this comes from
- National Institute of Diabetes and Digestive and Kidney Diseases — Low Blood Glucose (Hypoglycemia)
- American Diabetes Association — Standards of Care in Diabetes
How this page was put together
Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarized or generalized beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.
Medical disclaimer
This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to your doctor, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 911.
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