When your blood sugar drops below 70 mg/dL, eat or drink 15 grams of fast-acting carbohydrates immediately, then wait 15 minutes and recheck. This approach, known as the 15-15 rule, is the standard first response recommended by the American Diabetes Association and the CDC. Acting quickly matters because low blood sugar can progress from mild shakiness to confusion, seizures, or loss of consciousness if left untreated.
How to Recognize a Low
Your body sends out physical warning signs first. Sweating, a racing heartbeat, trembling hands, sudden anxiety, and intense hunger are the earliest signals. These happen because your body is releasing stress hormones to try to push blood sugar back up on its own. Most people learn to recognize this cluster of feelings as a reliable early alarm.
If blood sugar keeps falling, the symptoms shift from physical to cognitive. You may have trouble concentrating, feel confused or irritable, or notice your vision blurring. Slurred speech, poor coordination, and disorientation are signs that your brain isn’t getting enough glucose. At this stage, treating the low becomes urgent, and you may need help from someone nearby.
The 15-15 Rule, Step by Step
Check your blood sugar with a meter or continuous glucose monitor. If it’s below 70 mg/dL, eat or drink something that delivers about 15 grams of fast-acting carbohydrates. Good options include:
- 3 to 4 glucose tablets
- Half a cup (4 oz) of juice or regular soda (not diet)
- 1 tablespoon of sugar or honey
- 1 tube of glucose gel
Wait 15 minutes, then recheck. If your blood sugar is still below 70, repeat with another 15 grams. Keep cycling through this process until you’re back above 70 mg/dL. Most lows resolve after one or two rounds.
Once your number is back in range, eat a balanced snack or small meal that includes both protein and longer-acting carbohydrates. Crackers with cheese, a sandwich with meat, or peanut butter on toast all work well. The fast-acting sugar you just consumed will wear off quickly, and without a follow-up snack, your blood sugar can drop right back down.
Why the Right Carbs Matter
The instinct during a low is to eat everything in sight. That’s the hunger talking, and it’s intense. But overloading on food typically sends blood sugar rocketing high an hour or two later, which creates a frustrating cycle of lows and highs. Sticking to 15 grams and waiting, even when it feels impossibly slow, gives you much better control over what happens next.
Choose simple sugars that hit your bloodstream fast. Chocolate, cookies, and ice cream contain fat that slows digestion and delays the rise in blood sugar. Glucose tablets are the most predictable option because each tablet is a measured dose with no fat or protein to slow things down. Juice and regular soda also work quickly. Keep a stash of your preferred option wherever you spend time: your nightstand, desk, car, and gym bag.
When Someone Else Needs to Step In
Severe lows can make it impossible to treat yourself. If someone near you is showing signs of severe hypoglycemia (slurred speech, disorientation, seizures, or unconsciousness), do not try to put food or liquid in their mouth. They could choke. This is when an emergency glucagon device becomes critical.
Glucagon is a hormone that signals the liver to release stored sugar into the bloodstream. It’s available as a nasal spray that requires no injection. A caregiver inserts the tip of the device into one nostril and presses the plunger. Each device contains a single dose and doesn’t need to be primed or tested beforehand. The person should respond within about 15 minutes. If glucagon isn’t available or the person doesn’t respond, call 911 immediately.
If you use insulin or take medications that can cause lows, make sure the people around you (family, roommates, close coworkers) know where your glucagon is stored and how to use it before an emergency happens. Practicing with an expired device or a training kit removes the guesswork during a real event.
Why Some People Stop Feeling Lows
Repeated episodes of low blood sugar can actually train your brain to stop sounding the alarm. When lows happen frequently, the normal stress-hormone response gets dialed down. Sweating, trembling, and hunger become muted or disappear entirely. This condition, sometimes called hypoglycemia unawareness, means your blood sugar can drop dangerously low without any warning signs at all.
People with hypoglycemia unawareness often don’t catch a low until they’re already confused or disoriented, which makes self-treatment much harder. If this sounds familiar, a continuous glucose monitor with low-glucose alarms can serve as an external warning system. These devices check your glucose every few minutes and alert you (or a caregiver’s phone) when levels start to fall, even while you’re asleep.
The good news is that hypoglycemia unawareness is often reversible. Carefully avoiding lows for several weeks can help restore your body’s ability to detect them. This usually means adjusting medication doses and temporarily targeting a slightly higher blood sugar range, which is something to work through with whoever manages your diabetes care.
Preventing the Next Low
Treating a low is straightforward once you know the steps. Preventing the next one requires figuring out why it happened. Common triggers include skipping or delaying meals, exercising more than usual, taking too much insulin, or drinking alcohol without eating. Keeping a brief log of your lows (time, possible cause, what you ate beforehand) can reveal patterns that are easy to miss in the moment.
Timing food around physical activity makes a big difference. If you’re planning a workout, checking your blood sugar before you start and having a carbohydrate snack on hand can keep you from dropping mid-exercise. Alcohol deserves special attention because it blocks the liver from releasing stored sugar, which means lows can hit hours after your last drink, sometimes in the middle of the night.
Keeping fast-acting carbs within arm’s reach at all times is the simplest and most important habit. A low that takes 30 seconds to treat when you have glucose tablets in your pocket becomes a much bigger problem when you have to search for something to eat while your thinking is already getting foggy.