The fastest way to raise blood sugar is to eat or drink 15 grams of fast-acting carbohydrates, then wait 15 minutes and recheck. This approach, often called the Rule of 15, is the standard recommended by the American Diabetes Association and works whether your blood sugar has dipped mildly or dropped to a level that needs urgent attention. What you eat afterward matters too, because without a follow-up snack, your blood sugar can crash right back down.
Recognizing Low Blood Sugar
Blood sugar below 70 mg/dL is considered low. At that level, your body triggers an adrenaline-like response: sweating, shakiness, a racing heart, anxiety, and sudden hunger. These warning signs are your body’s alarm system, and they tend to come on fast.
If blood sugar keeps falling below 54 mg/dL, the brain itself starts running short on fuel. That’s when symptoms shift to weakness, dizziness, difficulty concentrating, confusion, blurred vision, and behavior that others sometimes mistake for intoxication. At this stage, you need to act immediately. If blood sugar drops low enough to impair your ability to help yourself, that’s classified as a severe episode, and someone nearby will need to step in.
The Rule of 15: Step by Step
The Rule of 15 is straightforward. Consume 15 grams of fast-acting carbohydrates. Wait 15 minutes. Test your blood sugar again. If it’s still below 70 mg/dL, repeat with another 15 grams. Keep cycling through until your numbers come back up.
The key word here is “fast-acting.” You want simple sugar that hits your bloodstream quickly, not something your body has to break down first. Good options for roughly 15 grams of fast-acting carbs include:
- Glucose tablets: 3 to 4 tablets, depending on the brand (check the label)
- Fruit juice: about 4 ounces (half a cup)
- Regular soda: about 4 ounces (not diet)
- Glucose gel: one tube
- Hard candies: a small handful, such as 5 to 6 Lifesavers
- A tablespoon of honey or sugar
One important detail: avoid reaching for chocolate, peanut butter, ice cream, or other foods high in fat or protein as your first treatment. Fat slows digestion and delays the sugar from reaching your bloodstream. Save those foods for after you’ve stabilized.
Following Up to Prevent a Second Drop
Fast-acting carbs raise your blood sugar quickly, but they also burn off quickly. If you stop there, your levels can plummet again within an hour or two. Once your blood sugar is back above 70 mg/dL, eat a balanced snack or small meal that combines longer-lasting carbohydrates with protein. Crackers with cheese, a sandwich with meat, or toast with peanut butter all work well. The protein and complex carbs digest more slowly, keeping your blood sugar stable for the next few hours.
If your next full meal is more than an hour away, this follow-up snack is especially important. Skipping it is one of the most common reasons people experience a second low shortly after treating the first one.
When Someone Else Needs Your Help
If the person is conscious and able to swallow, give them a fast-acting sugar source like juice or regular soda, then follow up with a snack that includes protein and carbs once they’re feeling better. Do not try to put food or liquid into the mouth of someone who is unconscious or too confused to swallow safely, as they could choke.
For severe episodes where someone can’t treat themselves, emergency glucagon is the go-to treatment. Glucagon is a hormone that signals the liver to release stored sugar into the bloodstream. Modern glucagon products are designed to be simple enough for a family member, coworker, or school nurse to use without medical training. A nasal spray version (Baqsimi) works like any nasal spray: you insert it into one nostril and press the plunger. Pre-filled injection pens (like the Gvoke HypoPen) go under the skin of the arm, belly, or thigh, similar to an EpiPen. Traditional glucagon kits require mixing a powder with liquid before injecting, which makes them slightly more complicated under pressure.
Anyone who takes insulin should have a glucagon product prescribed and keep it accessible. Just as important, the people around you need to know where it is and how to use it before an emergency happens.
Why Some People Don’t Feel the Warning Signs
Some people, particularly those who experience frequent lows, gradually lose the ability to feel early symptoms like shakiness and sweating. This is called impaired hypoglycemia awareness, and it’s dangerous because blood sugar can drop to critical levels without any internal alarm going off. The condition develops because repeated low episodes essentially train the body to stop sending warning signals.
The good news is that awareness can often be restored. The primary strategy is to carefully avoid all low blood sugar episodes for several weeks, which allows the body’s warning system to reset. This typically requires adjusting medications and using a continuous glucose monitor (CGM). CGMs check glucose levels every five minutes and can alert you with an alarm when your blood sugar starts trending low, essentially acting as an external warning system when your body’s internal one has gone quiet.
Structured education programs also help. These teach people to recognize subtle cues they might otherwise miss, like changes in coordination or mood, and to adjust insulin, food, and activity proactively rather than reactively. If you’ve had episodes where your blood sugar dropped below 54 mg/dL without you noticing, that pattern is worth bringing up at your next appointment, because it usually signals that your treatment plan needs adjustment.
Preventing Lows in the First Place
Treating a low is important, but preventing one is better. Most hypoglycemia in people with diabetes is caused by insulin, sulfonylureas, or similar medications that can push blood sugar too far down. Eating meals on a consistent schedule, not skipping meals, and adjusting carbohydrate intake around physical activity all reduce your risk. Exercise, in particular, can lower blood sugar for hours afterward, so having a snack before or during prolonged activity makes a real difference.
If you’re experiencing lows more than once or twice a week, or if you’ve had any episode severe enough to need help from another person, the American Diabetes Association recommends reevaluating your medication regimen. That could mean lowering your insulin dose, switching to a medication class with a lower risk of causing lows, or adding a CGM to catch drops before they become dangerous. One or more episodes of blood sugar falling below 54 mg/dL is a clear signal that something in the current plan isn’t working.
Keeping fast-acting carbs within reach at all times (in your bag, car, nightstand, and desk) is a small habit that makes a big difference when your blood sugar drops unexpectedly. Glucose tablets are particularly convenient because they don’t melt, spoil, or spill, and each tablet delivers a precise amount of sugar.