When your blood sugar drops below 70 mg/dL, you need fast-acting sugar immediately. The standard approach is called the 15-15 rule: eat 15 grams of quick carbohydrates, wait 15 minutes, then recheck your blood sugar. If it’s still low, repeat. Most mild episodes resolve within minutes when treated this way, but knowing exactly what to eat, what symptoms to watch for, and how to prevent a rebound drop makes a real difference.
Recognize the Symptoms Early
Low blood sugar triggers two waves of symptoms. The first wave is your body’s stress response: sweating, shaking, a pounding or racing heart, sudden anxiety, and intense hunger. These are your early warning signs, and acting on them quickly is the goal.
If blood sugar keeps falling, a second wave hits as your brain starts running short on fuel. This shows up as confusion, difficulty concentrating, irritability, slurred speech, and blurred vision. At this stage, decision-making gets harder, which is why it helps to have a plan (and supplies) ready before you ever need them. Below 54 mg/dL is considered severe hypoglycemia, and it can lead to seizures or loss of consciousness.
The 15-15 Rule
As soon as you feel symptoms or your meter reads below 70 mg/dL, eat or drink something that delivers about 15 grams of fast-acting carbohydrates. Good options include:
- 3 glucose tablets (the fastest, most predictable option)
- Half a cup (4 ounces) of fruit juice or regular soda
- 1 tablespoon of sugar (dissolved in water or eaten straight)
- 6 or 7 hard candies
Wait 15 minutes, then check your blood sugar again. If it’s still below 70, eat another 15 grams and recheck in another 15 minutes. Repeat until your levels come back up. The key is resisting the urge to overeat. When you feel shaky and starving, it’s tempting to raid the kitchen, but overcorrecting can send your blood sugar soaring in the other direction.
Stick to simple sugars for this step. Foods with fat or protein, like chocolate or peanut butter crackers, slow digestion and delay the sugar from reaching your bloodstream when you need it most.
Follow Up With a Real Snack
Once your blood sugar is back above 70, you’re not done. The fast-acting sugar you just consumed will burn off quickly, and without a follow-up snack or meal, your levels can drop again. Eat something that combines about 15 grams of carbohydrates with some protein to keep your blood sugar stable for the next few hours.
Practical combinations that work well: half a sandwich with meat or peanut butter, crackers with cheese, a small piece of fruit with an ounce of cheese, apple slices with peanut butter, or a handful of crackers with tuna salad. The protein slows the digestion of the carbs, giving you a longer, steadier rise instead of another spike and crash. If a full meal is coming within the next 30 to 60 minutes, you can skip the snack and just eat your meal.
What to Do in a Severe Episode
If someone with diabetes becomes confused, loses consciousness, or has a seizure from low blood sugar, do not try to put food or liquid in their mouth. They could choke. This is when glucagon is needed. Glucagon is an emergency hormone that signals the liver to release stored sugar into the bloodstream, and it works even when the person can’t swallow.
Glucagon comes in a few forms: a nasal spray that doesn’t require any injection, an auto-injector similar to an EpiPen that goes into the thigh or upper arm, and a traditional injection kit. If you live with or care for someone who uses insulin, know where their glucagon is stored and how to use it before an emergency happens. After giving glucagon, call for medical help. Once the person is conscious and able to swallow, give them something to eat to replenish the sugar their liver just released.
Common Triggers to Watch For
Most low blood sugar episodes come down to a mismatch between insulin (or certain diabetes medications) and the sugar available in your blood. The most common triggers fall into a few categories.
Skipping or delaying meals is a big one, especially if you’ve already taken insulin or medication timed to a meal. Exercise increases how quickly your muscles pull sugar from the blood, so a workout that’s longer or harder than usual can cause a drop, sometimes hours afterward. Alcohol is particularly risky because it blocks the liver from releasing stored sugar, which means your usual safety net isn’t there. Drinking on an empty stomach amplifies this effect.
Taking too much insulin, whether from a dosing error or misjudging carb intake at a meal, is another frequent cause. Hot weather, illness, and changes in routine can also shift your blood sugar in unexpected ways. Tracking when your lows happen can help you and your care team spot patterns and adjust your plan before the next episode.
Staying Prepared
The best thing you can do is make sure you’re never caught without fast-acting sugar. Keep glucose tablets or a small juice box in your bag, your car, your desk at work, and on your nightstand. Nighttime lows are especially common and easy to sleep through, so if you use insulin, checking before bed and keeping supplies within arm’s reach matters.
Wearing a medical ID bracelet or keeping an alert on your phone helps others help you if you can’t communicate during a severe episode. If you carry glucagon, check the expiration date regularly and make sure at least one person you’re often around knows where it is and how to use it.