The fastest way to raise your blood sugar is to eat 15 grams of fast-acting carbohydrates, such as four ounces of fruit juice, a tablespoon of honey, or a few glucose tablets. If your blood sugar is below 70 mg/dL, this is the standard first step, and it typically starts working within minutes. How you follow up after that initial boost matters just as much for keeping your levels stable.
Recognizing Low Blood Sugar
Low blood sugar, or hypoglycemia, is generally defined as a blood glucose reading below 70 mg/dL. Your body sends two distinct waves of warning signs as levels drop. The first wave is physical: sweating, shaking, a racing heartbeat, anxiety, and sudden hunger. These happen because your nervous system is firing stress signals to push glucose into your bloodstream.
If levels keep falling, you’ll notice a second set of symptoms that are more cognitive. Confusion, difficulty concentrating, irritability, and blurred or altered vision all point to your brain not getting enough fuel. At its most severe, low blood sugar can cause loss of consciousness or seizures. Recognizing the earlier physical symptoms gives you time to act before things escalate.
The 15-15 Rule
The CDC recommends a simple protocol called the 15-15 rule: eat 15 grams of fast-acting carbohydrates, wait 15 minutes, then check your blood sugar again. If it’s still below 70 mg/dL, repeat the process. Keep going until your reading is back in your target range.
The key word here is “fast-acting.” You want carbohydrates that hit your bloodstream quickly, without fat or fiber slowing digestion. Good options that deliver roughly 15 grams of carbs include:
- 4 ounces (half a cup) of fruit juice like apple or orange juice
- 4 ounces of regular soda (not diet)
- 1 tablespoon of honey or sugar
- Glucose tablets (follow the package for the right number, usually 3 to 4)
- Hard candies like jelly beans or gumdrops (check labels for carb count)
Avoid reaching for chocolate bars, cookies, or ice cream. The fat in these foods slows absorption significantly, meaning your blood sugar takes longer to recover when you need it rising right now.
Stabilizing After the Initial Fix
Fast-acting carbs raise your blood sugar quickly, but that spike can fade just as fast. Once your reading is back above 70 mg/dL, eat a small snack or meal that includes both complex carbohydrates and protein. A handful of crackers with peanut butter, cheese with whole-grain bread, or a small portion of meat with a starchy side all work well. The protein slows digestion and helps prevent your blood sugar from crashing again within the next hour or two.
Skipping this follow-up step is one of the most common mistakes. People feel better after the juice or glucose tablets and go back to what they were doing, only to drop low again 30 to 60 minutes later.
When Someone Can’t Treat Themselves
Severe hypoglycemia means the person’s blood sugar has dropped so low they can’t eat or drink safely on their own. They may be confused, unresponsive, or unconscious. Never try to put food or liquid in the mouth of someone who can’t swallow, as this creates a choking risk.
Glucagon is the emergency treatment for this situation. It’s a hormone that signals the liver to release stored glucose. A nasal spray version is available that requires no injection. You insert the tip into one nostril and press the plunger until the dose is delivered. The person doesn’t even need to inhale it. If there’s no response after 15 minutes, a second dose from a new device can be given. Call emergency services immediately after administering the first dose. Once the person is alert enough to swallow, give them something to eat to replenish their glucose stores and prevent another drop.
If you take insulin or medications that can cause low blood sugar, keeping a glucagon kit accessible and making sure the people around you know how to use it can be lifesaving.
Why Blood Sugar Drops in the First Place
For people with diabetes, the most common triggers are taking too much insulin, delaying or skipping a meal, or exercising more than usual without adjusting food intake. Alcohol also lowers blood sugar because it interferes with the liver’s ability to release glucose.
People without diabetes can experience low blood sugar too. Reactive hypoglycemia causes blood sugar to drop within four hours after eating, often after meals high in refined carbs. The body overproduces insulin in response to a rapid sugar spike, and levels crash on the other side. Other less common causes include certain types of tumors, inherited metabolic conditions, and gastric bypass surgery, which changes how quickly food moves through the digestive system.
Exercise and Blood Sugar Swings
Aerobic exercise like walking, jogging, or cycling burns both fat and glucose for fuel, which can pull your blood sugar down during or after a session. If you’re prone to lows, checking your blood sugar before a workout and having a carb-rich snack ready is a practical safeguard.
Anaerobic exercise tells a different story. High-intensity activities like sprinting or heavy weight lifting pull glycogen directly from your muscles and can actually cause blood sugar to rise for up to an hour after the session. This spike is temporary and driven by stress hormones, not by eating. Over time, anaerobic exercise improves how well your body responds to insulin, so the short-term bump is more than offset by long-term benefits. Knowing which direction your blood sugar tends to move with different types of exercise helps you plan meals and snacks accordingly.
Preventing Repeated Episodes
If you’re treating low blood sugar regularly, the pattern itself is worth paying attention to. Frequent lows can dull your body’s warning signals over time, a phenomenon called hypoglycemia unawareness. Your sweating and shaking responses become muted, which means you may not notice a drop until it becomes severe.
Practical steps to reduce the frequency of episodes include eating meals and snacks at consistent times, pairing carbohydrates with protein or healthy fat to slow absorption, monitoring blood sugar more closely around exercise, and being cautious with alcohol, especially on an empty stomach. If you take insulin or blood sugar-lowering medication, tracking the timing and dose alongside your meals and activity can reveal patterns that make adjustments possible.