The fastest way to get your glucose up is to eat or drink 15 grams of fast-acting carbohydrates, then wait 15 minutes and recheck your blood sugar. This approach, called the 15-15 rule, is the standard method recommended for treating blood sugar below 70 mg/dL. Most people feel noticeably better within 10 to 15 minutes, but the specific foods you choose and what you do afterward both matter for a full recovery.
Recognizing Low Blood Sugar
Before you treat the problem, it helps to know what it feels like. Early signs of low blood sugar include shakiness, sweating, a fast heartbeat, sudden hunger, and feeling anxious or irritable. You might also notice dizziness, difficulty concentrating, or tingling in your lips or tongue.
If blood sugar continues to drop, symptoms get more serious: confusion, slurred speech, blurry vision, and loss of coordination. Severe lows can cause seizures or loss of consciousness. The goal is to catch it early and act fast, before mild symptoms escalate.
The 15-15 Rule Step by Step
When your blood sugar reads below 70 mg/dL (or you’re experiencing symptoms and can’t test), follow this sequence:
- Eat or drink 15 grams of fast-acting carbohydrates. Options include 4 to 5 glucose tablets, 2/3 cup of fruit juice or regular soda (not diet), 1 tablespoon of honey, 1 tablespoon of sugar dissolved in water, or 6 hard candies like Life Savers.
- Wait 15 minutes. Give the sugar time to reach your bloodstream. Resist the urge to eat everything in sight, which can cause a rebound spike later.
- Recheck your blood sugar. If it’s still below 70 mg/dL, repeat the process: another 15 grams of carbs, another 15-minute wait.
- Eat a balanced snack or meal. Once your reading is back in your target range, follow up with something that includes both protein and carbohydrates (crackers with peanut butter, cheese and fruit, or a small meal). This prevents your glucose from crashing again.
Glucose tablets are the preferred choice because they contain a precise amount of sugar and work predictably. Juice and soda work well too, but it’s easy to misjudge the portion. Chocolate and ice cream are poor choices in the moment because their fat content slows sugar absorption.
What to Do for Children
Young children, especially infants and toddlers, need less than 15 grams. A general guideline is about 0.3 grams of glucose per kilogram of body weight. In practical terms, a 30-kilogram child (about 66 pounds) needs roughly 9 grams, while a 50-kilogram child (about 110 pounds) needs the full 15 grams. Glucose tablets can be broken in half for smaller doses, and small amounts of juice are often easiest for young kids to take quickly.
When Someone Can’t Eat or Drink
If a person is confused, unconscious, or having a seizure, do not try to put food or liquid in their mouth. They could choke. This is when emergency glucagon becomes necessary.
Glucagon is a hormone that signals the liver to release stored sugar into the bloodstream. It’s available as a nasal powder that requires no inhalation. You simply insert the device into one nostril and press the plunger. The dose is 3 milligrams for adults and children 1 year and older, and a second dose can be given after 15 minutes if there’s no response. Injectable forms are also available. After giving glucagon, call emergency services. Once the person is alert enough to swallow, offer juice or soda followed by a snack with protein.
If you or someone in your household is at risk for severe lows, keeping a glucagon kit accessible (and making sure family members know where it is and how to use it) can be lifesaving.
Why Blood Sugar Drops
For people with diabetes, the most common triggers are too much insulin or other glucose-lowering medication, skipping or delaying meals, drinking alcohol, and exercising more intensely or longer than usual. Even a change in routine, like eating lunch two hours later than normal, can be enough to cause a dip.
Low blood sugar also happens in people without diabetes. Reactive hypoglycemia causes a glucose drop within four hours after eating, often after a meal heavy in refined carbohydrates. The exact mechanism isn’t always clear, but the body essentially overproduces insulin in response to the meal, pulling blood sugar down too far. Other causes include alcohol consumption, prior bariatric surgery, certain inherited metabolic conditions, and rarely, tumors that affect insulin production.
Preventing Lows During Exercise
Physical activity pulls glucose out of your bloodstream and into your muscles for fuel, which is why exercise is one of the most common triggers for low blood sugar. If you take insulin or medications that lower glucose, eating a small carbohydrate-containing snack before a workout can help keep levels stable. For longer sessions (anything beyond 30 to 60 minutes of moderate or intense activity), you may need additional carbs during the exercise as well. Checking your blood sugar before, during, and after exercise helps you learn your own patterns and figure out how much fuel you need.
Understanding Severity Levels
Not all lows are equally dangerous. Clinicians classify hypoglycemia into three levels that are useful to understand:
- Level 1: Blood sugar between 54 and 69 mg/dL. You’ll likely feel symptoms but can treat it yourself with the 15-15 rule.
- Level 2: Blood sugar below 54 mg/dL. This is clinically significant and needs immediate treatment. Symptoms are typically more intense, and your ability to think clearly may already be impaired.
- Level 3: A severe event where you need someone else’s help to recover, regardless of the exact number on the meter. This is when glucagon or emergency medical care is necessary.
Most episodes are Level 1 and resolve quickly with a snack and a few minutes of patience. The key is treating them promptly so they don’t progress. If you’re experiencing frequent lows (more than a couple of times per week), that pattern usually signals a need to adjust your medication, meal timing, or activity level.