The fastest way to raise low blood sugar is to eat 15 grams of fast-acting carbohydrates, which typically brings your levels back up within 15 minutes. This approach, known as the 15-15 rule, is the standard method for treating a blood sugar drop whether you have diabetes or not. But how you follow up matters just as much as that initial fix, because without the right next step, your blood sugar can slide right back down.
Recognizing Low Blood Sugar
Blood sugar below 70 mg/dL is considered low. At that level, your body sends out early warning signals: shakiness, a pounding heart, sweating, sudden hunger, anxiety, and tingling in your lips or fingers. These are your body’s stress response kicking in, driven by adrenaline trying to push stored sugar out of your liver and into your bloodstream.
If blood sugar drops further, below 54 mg/dL, a different set of symptoms appears. These come from your brain not getting enough fuel: confusion, difficulty thinking, weakness, drowsiness, and feeling unusually warm. At this stage, you need to act immediately. A severe episode, where you become disoriented or lose consciousness and need someone else’s help, is a medical emergency regardless of your exact blood sugar number.
The 15-15 Rule for a Quick Fix
When your blood sugar is low, eat or drink 15 grams of fast-acting carbohydrates and wait 15 minutes. Then check your blood sugar again. If it’s still below 70 mg/dL, repeat the process until you’re back in your target range.
Any of these count as roughly 15 grams of fast-acting carbs:
- 3 glucose tablets
- Half a cup (4 ounces) of fruit juice or regular soda
- 6 or 7 hard candies
- 1 tablespoon of sugar
- 17 small grapes
- 1 extra-small banana (about 4 inches)
Glucose tablets are the most predictable option because they contain a precise amount of sugar and nothing else to slow absorption. Fruit juice works well too. Avoid chocolate, peanut butter cups, or ice cream as your first-line treatment. The fat in those foods slows digestion and delays the sugar from reaching your bloodstream when you need it most.
Following Up So It Doesn’t Drop Again
The 15-15 rule gets your blood sugar up quickly, but that spike from simple carbs fades fast. Once you’re back above 70 mg/dL, eat a balanced snack or meal that combines complex carbohydrates with protein. This pairing slows digestion and prevents your blood sugar from crashing again within an hour or two.
Good follow-up snacks (around 15 to 20 grams of carbs) include fresh fruit with a handful of mixed nuts, oatcakes with cheese, vegetable sticks with hummus and a breadstick, or a small pot of Greek yogurt. If it’s close to mealtime, go straight to eating. Whole-grain bread with eggs, a tuna sandwich on whole-wheat, or grilled chicken with brown rice and vegetables all provide the slow-burning fuel that keeps levels stable.
How Your Body Raises Blood Sugar on Its Own
Your body has built-in systems for raising blood sugar. When levels start to fall, your pancreas releases a hormone called glucagon. Glucagon signals your liver to break down its stored sugar (glycogen) and release it into your bloodstream. This process peaks about 15 minutes after glucagon is released, which is part of why the 15-minute waiting period in the 15-15 rule works the way it does.
Stress hormones also raise blood sugar. Adrenaline triggers the liver to release stored sugar and simultaneously slows the rate at which your muscles absorb it, creating a rapid spike. Cortisol, the longer-acting stress hormone, sustains this effect over hours. This is why blood sugar tends to run higher during illness, injury, or periods of intense emotional stress. For people with diabetes, the combination of adrenaline, cortisol, and glucagon can cause exaggerated spikes that are harder to manage.
Emergency Glucagon for Severe Episodes
If someone’s blood sugar drops so low that they can’t safely eat or drink, or they lose consciousness, they need emergency glucagon. This is a prescription product that delivers a concentrated dose of the same hormone your body uses naturally.
There are a few forms available. One is a nasal powder that gets sprayed into the nostril, requiring no injection at all. Another is a pre-filled auto-injector pen that works similarly to an EpiPen. A third option is a traditional injection kit that requires mixing the medication before use. If you or someone you live with is at risk for severe low blood sugar, it helps to have one of these on hand and to make sure household members know where it is and how to use it before an emergency happens.
Keeping Blood Sugar Stable Overnight
Nighttime lows are particularly risky because you’re asleep and may not notice the warning signs. If you tend to wake up with symptoms of low blood sugar, or if a continuous glucose monitor has flagged overnight dips, a bedtime snack that pairs complex carbs with protein or fat can help. Something like whole-grain toast with peanut butter, or a small bowl of oats with nuts, digests slowly enough to provide a steady trickle of glucose through the night.
If you use insulin, nighttime lows often relate to dosing. Adjusting the timing or amount of long-acting insulin is something to work through with your care team, but in the meantime, that bedtime snack acts as a buffer.
Low Blood Sugar Without Diabetes
Not everyone who experiences low blood sugar has diabetes. Reactive hypoglycemia causes blood sugar to drop two to four hours after eating, typically after a meal heavy in refined carbohydrates. Your body overproduces insulin in response to the sugar rush, then overshoots, sending your levels too low.
The dietary approach for reactive hypoglycemia focuses on preventing the spike-and-crash cycle rather than treating lows after they happen. That means choosing high-fiber, low-glycemic foods at every meal: whole grains instead of white bread, legumes like lentils and chickpeas, and always including a protein source such as eggs, fish, poultry, or tofu. Eating smaller, more frequent meals (every two to three hours) with about 40 to 50 grams of carbohydrates at main meals helps keep levels steady throughout the day.
Reactive hypoglycemia can sometimes be an early sign of insulin resistance, particularly if it runs alongside weight gain or a family history of diabetes. In those cases, the dietary changes serve double duty: raising and stabilizing blood sugar in the short term while reducing diabetes risk over time.