To raise low blood sugar fast, eat or drink 15 grams of fast-acting carbohydrate and recheck in 15 minutes — the American Diabetes Association’s Rule of 15. Good options include 4 ounces (120 mL) of juice or regular soda, 3 to 4 glucose tablets, 1 tablespoon of honey or table sugar, or 8 to 10 jelly beans. If the person is confused, cannot swallow, or is unresponsive, call 911 and use glucagon if available — never put food into an unconscious person’s mouth.
How Low Is “Low”?
The ADA classifies low blood sugar (hypoglycemia) in three levels:
| Level | Blood Glucose | What to Do |
|---|---|---|
| Level 1 (alert) | 70 mg/dL or less but above 54 mg/dL (3.9 or less but above 3.0 mmol/L) | Rule of 15: 15 g fast carbs, wait 15 min, recheck |
| Level 2 (clinically significant) | Below 54 mg/dL (below 3.0 mmol/L) | Rule of 15 with 20 g instead; may need second round; consider glucagon if symptoms are severe |
| Level 3 (severe) | Altered consciousness, seizure, or inability to self-treat | Call 911; give glucagon; do not put food in mouth |
Exactly What 15 Grams of Fast Carbs Looks Like
These options all deliver roughly 15 grams of quickly-absorbed carbohydrate:
- 3 to 4 glucose tablets (each is typically 4 g)
- 1 tube of glucose gel (15 g) — designed for this purpose
- 4 ounces / 120 mL of juice (orange, apple, or grape)
- 4 ounces of regular (not diet) soda
- 1 tablespoon of sugar or 2 to 3 teaspoons dissolved in water
- 1 tablespoon of honey (slightly slower than glucose; acceptable)
- 8 to 10 regular jelly beans
- 5 to 6 Life Savers or similar hard candies (chewed, not sucked)
- 1 tablespoon of maple syrup
- 2 tablespoons of raisins (slightly slower due to fiber)
Foods to Avoid During the First 15 Minutes
These sound like they should work but slow down absorption because of fat, protein, or fiber:
- Chocolate, candy bars with nougat or caramel
- Peanut butter or peanut butter crackers
- Ice cream or milk with full fat
- Granola bars with nuts and oats
- Whole fruit (apple, banana) — slower than juice
- Cookies or baked goods
Use these after the Rule of 15 brings glucose back to target and only if the next meal is more than an hour away.
The Rule of 15 Step by Step
- Check your blood sugar if you can. If you feel the symptoms of a low (shakiness, sweating, pounding heart, hunger, confusion, blurred vision) and do not have a meter within 30 seconds, treat first.
- Consume exactly 15 grams of fast-acting carbs from the list above.
- Sit down, wait 15 minutes. Do not drive, operate machinery, or exercise.
- Recheck your blood sugar.
- If still under 70 mg/dL, repeat with another 15 grams.
- Once above 70 mg/dL and stable, if the next meal is more than an hour away, eat a small balanced snack — a slice of whole-grain toast with a scrape of peanut butter, crackers with cheese — to prevent another drop.
- Log the event: time, glucose value, what caused it (missed meal, extra insulin, exercise), and how you treated it. Share with your care team.
For a detailed walk-through of the same steps, see our companion guide on how to treat low blood sugar.
Severe Hypoglycemia: A 911 and Glucagon Situation
If a person with diabetes:
- Will not wake up
- Cannot answer simple questions
- Is having a seizure
- Is combative or confused enough to be unsafe
Then:
- Call 911.
- Do not put food or liquid into their mouth — aspiration can kill.
- If a glucagon kit is available, give it now. Modern options (Gvoke HypoPen, Baqsimi nasal spray, Zegalogue) are designed for non-medical family members and work within 10 to 15 minutes.
- Place the person on their side (recovery position) to protect the airway.
- When they wake, they may be nauseous. Offer sips of juice or glucose gel once alert enough to swallow safely, then a small meal.
Every person on insulin or sulfonylureas should have an unexpired glucagon kit at home and at least one family member, roommate, or coworker trained in its use.
What If the Low Is Nocturnal?
If you wake up sweaty, headachy, and shaky, treat it immediately — check first if you can, but if you clearly feel a low, go straight to glucose tablets or juice at the bedside. Then follow up with a small carb-plus-protein snack before going back to sleep to prevent a repeat. Patterns of overnight lows should prompt a medication review with your doctor. Our guide on symptoms of blood sugar dropping at night covers prevention.
What Causes a Low?
- Too much insulin relative to carbs eaten
- Taking a sulfonylurea and skipping or delaying a meal
- Unplanned or longer-than-usual exercise
- Drinking alcohol, especially on an empty stomach
- Weight loss or new diet with lower carbs (insulin needs may have changed)
- Kidney dysfunction changing how medications are cleared
- Vomiting or diarrhea after insulin was already given
Identifying the trigger helps prevent repeats — look at the last 4 to 6 hours before the low.
Stock Your Low-Sugar Toolkit
Keep at least two of the following within reach at home, at work, in your car, and in any bag you carry:
- Glucose tablets (long shelf life, exact dose)
- A juice box or small regular soda
- A tube of glucose gel
- A glucagon kit (nasal spray or prefilled injection) for severe lows
- A glucose meter or CGM
- A medical ID bracelet or card
Check expiration dates every 6 months and replace anything past its date.
The Bottom Line
If your blood sugar is low, eat exactly 15 grams of fast-acting carbs — glucose tablets, juice, regular soda, or honey — and wait 15 minutes before deciding what to do next. Skip chocolate, peanut butter, and whole fruit in the first 15 minutes; the fat slows absorption. For unconscious or confused people, call 911 and use glucagon. Prevention is about knowing your triggers, adjusting insulin or sulfonylurea doses when exercise, meals, or alcohol change, and keeping a low-sugar toolkit within arm’s reach everywhere you go.
