The fastest way to raise your glucose level is to eat or drink 15 grams of fast-acting carbohydrates, then wait 15 minutes and recheck. Blood sugar below 70 mg/dL is considered low, and below 54 mg/dL is considered severely low. How you respond depends on how low your levels are, whether you have diabetes, and whether episodes happen regularly.
Recognizing Low Blood Sugar
Your body sends two waves of warning signals when glucose drops too low. The first wave comes from stress hormones flooding your system: sweating, trembling or feeling shaky, a rapid heartbeat, sudden anxiety, and intense hunger. These symptoms are your body’s alarm system, and they typically appear while you can still act on your own.
If glucose keeps falling, a second set of symptoms appears as your brain runs short on fuel. These include headache, dizziness, blurred vision, difficulty concentrating, poor coordination, confusion, weakness, and tingling in the lips or hands. At this stage, thinking clearly becomes harder, which is exactly why it’s important to act during that first wave of symptoms rather than waiting.
The 15-15 Rule for Quick Recovery
The standard approach is straightforward: consume 15 grams of fast-acting sugar, wait 15 minutes, then test your blood sugar again. If it’s still below 70 mg/dL, repeat with another 15 grams. Here’s what 15 grams of fast-acting carbohydrate looks like in practice:
- Glucose or dextrose tablets: 4 to 5 tablets (the preferred option because the dosing is precise)
- Fruit juice or regular soda: two-thirds of a cup (about 150 mL), not diet versions
- Honey: 1 tablespoon
Glucose tablets work fastest because they contain pure glucose that enters your bloodstream without needing to be broken down. Juice and honey are effective alternatives when tablets aren’t available. Diet soda and sugar-free drinks will not raise your glucose at all.
Follow Up With Protein and Complex Carbs
Fast-acting sugar solves the immediate problem, but it burns through quickly. After your blood sugar comes back above 70 mg/dL, eat a balanced snack or small meal that combines protein with longer-acting carbohydrates. Crackers with cheese, a sandwich with meat, or peanut butter on whole-grain bread all work well. The protein and fat slow digestion, keeping your glucose stable instead of letting it spike and crash again.
Skipping this follow-up step is one of the most common mistakes. Without it, your blood sugar can drop right back down within an hour or two.
When Someone Can’t Treat Themselves
Severe low blood sugar, below 54 mg/dL, can cause confusion, loss of consciousness, or seizures. If someone has collapsed, is having a seizure, has trouble breathing, or can’t be woken up, call 911 immediately.
If the person is conscious and able to swallow, give them a fast-acting sugar source like juice or regular soda, followed by longer-acting carbs with protein once they’re alert. Never try to give food or liquid to someone who is unconscious or unable to swallow safely.
For people at risk of severe episodes, prescription glucagon is available as a nasal powder, an auto-injector, or a prefilled syringe. If someone doesn’t wake up within 15 minutes after a glucagon injection, a second dose can be given while waiting for emergency help. Having glucagon on hand and making sure the people around you know how to use it can be lifesaving.
Preventing Drops During Exercise
Physical activity pulls glucose out of your bloodstream to fuel working muscles, which is why exercise is a common trigger for low blood sugar, particularly in people with type 1 diabetes. For moderate aerobic exercise lasting an hour or more, current recommendations suggest consuming 30 to 60 grams of carbohydrates per hour to prevent a drop. A more precise approach is roughly 0.5 grams of carbohydrate per kilogram of body weight per hour, which works out to about 35 grams for a 70-kilogram (154-pound) person.
Timing matters too. Taking a larger carbohydrate dose 30 minutes before exercise tends to spike glucose levels significantly, while splitting the same amount into smaller portions before and during the activity keeps levels more stable. If you exercise regularly and notice post-workout lows, experimenting with smaller, distributed carb intake rather than one large pre-workout snack often produces better results.
Reactive Hypoglycemia Without Diabetes
Some people experience blood sugar drops one to four hours after eating, even without diabetes. This is called reactive hypoglycemia, and it’s driven by an oversized insulin response to a meal rather than by fasting or medication. The symptoms feel the same (shakiness, sweating, brain fog), but the long-term management strategy is different.
If you’re having a reactive episode right now, treat it the same way: 15 grams of fast-acting carbs, wait, recheck. But to prevent future episodes, the approach flips. Instead of reaching for quick sugar, you want to avoid the foods that trigger the insulin overshoot in the first place. That means cutting back on simple sugars and refined carbohydrates like sweetened drinks, white bread, and pastries.
Replace those with low glycemic index foods: complex carbohydrates that are high in fiber and digest slowly. Pair them with protein and healthy fat at every meal. Adding fat and protein slows your body’s digestion of carbs further, preventing the sharp glucose spike that leads to the crash afterward. Eating smaller meals or snacks every two to four hours, rather than two or three large meals, also helps keep your blood sugar on a more even keel throughout the day.