Hypoglycemia: Common Questions
Blood glucose falling too low, usually in people taking insulin or sulfonylureas.
Last revised
Hypoglycemia: the questions people actually ask, answered from published guidance.
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 get help" below apply to you.
What is Hypoglycemia?
Blood glucose falling too low, usually in people taking insulin or sulfonylureas.
Why does it matter?
It can develop quickly, impairs judgment exactly when judgment is needed, and is dangerous while driving.
Commonly defined as for Hypoglycemia?
Below 70 mg/dL.
Early symptoms for Hypoglycemia?
Shakiness, sweating, hunger, anxiety, fast heartbeat.
Immediate treatment for Hypoglycemia?
15 g of fast-acting carbohydrate (the 15-15 rule).
Recheck after for Hypoglycemia?
15 minutes, and repeat if still below 70 mg/dL.
What is the single most useful thing to do?
Carry fast-acting carbohydrate, such as glucose tablets or juice, at all times.
What is the most common mistake?
Driving when your glucose is low or you feel any symptoms.
When should I see 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.
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
- Hypoglycemia: What Published Guidance Supports
- Making Sense of 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 get help
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.
