How to Treat Low Blood Sugar

Treat low blood sugar (hypoglycemia) with the American Diabetes Association Rule of 15: consume 15 grams of fast-acting carbohydrate, wait 15 minutes, then recheck your glucose. Good 15-gram options are 3 to 4 glucose tablets, 4 ounces (120 mL) of juice or regular soda, or 1 tablespoon of honey. For severe hypoglycemia — unconsciousness, seizure, inability to swallow — call 911 and use glucagon immediately.

How Low Is Low?

Warning Signs to Act On

Early (autonomic) symptoms are caused by adrenaline trying to raise glucose:

• Shakiness or trembling
• Sweating (often cold and clammy)
• Pounding or racing heart
• Sudden hunger
• Anxiety or a vague sense that something is wrong
• Pale skin
• Tingling around the mouth

Late (neuroglycopenic) symptoms mean the brain is running out of fuel and must be treated urgently:

• Confusion or difficulty concentrating
• Slurred speech
• Blurry or double vision
• Dizziness, weakness, staggering
• Irritability, unusual behavior
• Headache
• Seizure or unconsciousness (severe)

Step-by-Step: The Rule of 15

1. Check your glucose if you can. If you cannot within 30 seconds and symptoms are clear, treat first.
2. Consume 15 grams of fast-acting carbohydrate (see list below).
3. Sit down, stop activity, do not drive.
4. Wait 15 minutes — not 5 or 10; the Rule is the Rule for a reason.
5. Recheck your glucose.
6. If still under 70 mg/dL, repeat the 15 grams and wait another 15 minutes.
7. Once stable above 70 mg/dL, if the next meal is more than an hour away, eat a small balanced snack (crackers with cheese, half a sandwich) to prevent another drop.
8. Log the event, the glucose value, and what you think caused it. Share with your care team.

Exactly 15 Grams of Fast Carbs

• 3 to 4 glucose tablets (each 4 g)
• 1 tube of glucose gel (15 g)
• 4 oz (120 mL) juice — orange, apple, or grape
• 4 oz (120 mL) regular (not diet) soda
• 1 tablespoon sugar dissolved in a little water
• 1 tablespoon honey
• 8 to 10 jelly beans
• 5 to 6 Life Savers, chewed
• 1 tablespoon maple syrup

For a richer food-by-food walkthrough, see what to eat to get blood sugar up.

Do Not Use These First

These delay absorption and let the low drag on:

• Chocolate, candy bars, ice cream (fat slows absorption)
• Peanut butter alone
• Whole-fruit bananas or apples (fiber slows absorption; use juice instead)
• Granola bars with nuts and oats
• Cookies, baked goods

Save these for the follow-up snack after the low is already resolved.

Severe Hypoglycemia: 911 and Glucagon

If the person is confused, uncooperative, unconscious, or having a seizure:

1. Call 911 immediately.
2. Do not put food or drink into their mouth — aspiration risk.
3. Give glucagon now if a kit is available. Modern options include:
   • Baqsimi — nasal spray; 3 mg puff; works within 15 minutes; no refrigeration, no mixing.
   • Gvoke HypoPen / Gvoke PFS — prefilled autoinjector or syringe with ready-to-use glucagon.
   • Zegalogue — dasiglucagon autoinjector; works rapidly.
   • Traditional glucagon emergency kit — requires reconstitution; older but still used.
4. Place the person on their side (recovery position).
5. When they wake, they are often nauseous. Offer sips of juice or a small snack once they can swallow safely. Expect some confusion for 15 to 30 minutes.
6. Seek medical evaluation even after recovery — severe hypoglycemia needs a medication review.

Every household with a person on insulin or sulfonylureas should have an unexpired glucagon kit and at least one other person who knows where it is and how to use it. Check the expiration every 6 months.

Common Causes of Lows

• More insulin (or a sulfonylurea like glipizide, glyburide, glimepiride) than the carbs eaten required
• Skipped or delayed meal
• Unplanned or longer-than-usual exercise
• Alcohol, especially on an empty stomach
• Recent weight loss or a lower-carb diet without a medication adjustment
• Kidney function changes (medications stick around longer)
• Vomiting or diarrhea after insulin was already injected
• Incorrect injection technique (intramuscular instead of subcutaneous)

Hypoglycemia Unawareness

Repeated lows — especially overnight — can blunt the body’s adrenaline warning system, so early symptoms disappear. If sweating, shakiness, or hunger no longer warn you before you become confused, you have hypoglycemia unawareness. Treatment is usually relaxing glucose targets temporarily and using a continuous glucose monitor with low-glucose alarms to rebuild warning symptoms. Talk to your doctor promptly. See our related guide on overnight blood sugar drops.

Preventing the Next Low

• Know your target range and treat below 70 mg/dL promptly.
• Always carry fast carbs — in a pocket, purse, bedside drawer, glove box, and gym bag.
• Match insulin doses to actual carbs eaten; do not dose and then skip food.
• Reduce insulin for planned exercise per your doctor’s rule of thumb.
• Eat a small bedtime snack if bedtime glucose is under 100 mg/dL on insulin.
• Avoid alcohol on an empty stomach.
• Use a CGM with low-glucose alarms if you have recurrent lows or hypoglycemia unawareness.
• Review any low that required help from another person with your diabetes team.

Related Reading

For broader management strategy, see our treatment hub and prediabetes symptoms overview.

The Bottom Line

Low blood sugar is treated with 15 grams of fast carbs, a 15-minute wait, and a recheck — the Rule of 15. Severe lows with altered consciousness or seizure need 911 and glucagon, not food. Prevention hinges on knowing your personal triggers, carrying fast carbs everywhere, training a family member on glucagon, and reviewing any serious low with your care team. Hypoglycemia is common in insulin and sulfonylurea users, but every episode is a chance to refine your regimen so the next one does not happen.