If your blood sugar drops below 70 mg/dL, eat or drink 15 grams of fast-acting carbohydrates immediately. This is the core of the “15-15 rule,” the standard approach recommended by diabetes organizations: consume 15 grams of quick sugar, wait 15 minutes, recheck your blood sugar, and repeat if it’s still below 70 mg/dL. Most mild to moderate episodes resolve within one or two rounds.
Recognizing Low Blood Sugar
Your body sends out early warning signals when blood sugar starts dropping. The first wave of symptoms comes from your nervous system kicking into alert mode: shakiness, sweating, a racing heartbeat, sudden anxiety, and intense hunger. These are your body’s way of telling you to eat something, and they’re the easiest stage to treat on your own.
If blood sugar continues to fall, a second set of symptoms appears as your brain starts running short on fuel. These include weakness, dizziness, difficulty concentrating, confusion, blurred vision, and behavior that others might mistake for intoxication. At this stage, you can still treat yourself, but you need to act quickly before things get worse. In extreme cases, untreated low blood sugar can lead to seizures or loss of consciousness.
The 15-15 Rule Step by Step
The goal is to get glucose into your bloodstream as fast as possible. Here’s the process:
- Step 1: Eat or drink 15 grams of fast-acting carbohydrates.
- Step 2: Wait 15 minutes. Your body needs time to absorb the sugar.
- Step 3: Check your blood sugar again. If it’s still under 70 mg/dL, repeat with another 15 grams.
- Step 4: Keep repeating until your blood sugar is back in your target range.
One important detail: avoid foods that are high in fat or fiber during this step. Chocolate, baked goods, beans, and whole fruit all slow down sugar absorption. You want the simplest, fastest-digesting carbohydrates you can find.
Best Fast-Acting Carbohydrate Sources
Each of these provides roughly 15 grams of fast-acting carbohydrates:
- 3 to 4 glucose tablets
- 1 tube of glucose gel
- ½ cup of fruit juice (apple or orange work well)
- ½ cup of regular soda (not diet)
- 1 tablespoon of sugar or honey
Glucose tablets and gel are the most precise options because they’re pre-measured and portable. If you’re prone to lows, keeping a tube of glucose tablets in your bag, car, or nightstand means you’re never caught without a fix. Juice and regular soda work nearly as well and are easier to find in most kitchens.
What to Eat After Your Blood Sugar Stabilizes
Once your blood sugar climbs back above 70 mg/dL, the fast-acting sugar you just consumed will burn off quickly. Without a follow-up snack, your blood sugar can drop right back down. The key is pairing a complex carbohydrate with some protein or fat to give yourself a slower, steadier source of energy.
Good follow-up snacks that combine about 15 grams of carbohydrates with protein include:
- Half a sandwich with meat, cheese, or peanut butter
- 8 animal crackers with 2 tablespoons of peanut butter
- A small piece of fruit with 1 ounce of cheese
- 6 saltine crackers with a quarter cup of tuna salad
- 3 cups of plain popcorn with a small handful of nuts
If your next full meal is more than an hour away, this follow-up snack is especially important. The protein and fat slow digestion enough to keep your blood sugar steady for the next couple of hours.
When Someone Else Needs to Step In
Severe low blood sugar, defined as an episode where a person’s mental or physical state is altered enough that they need help from someone else, requires a different approach. If someone is confused, unconscious, or unable to swallow safely, do not try to put food or liquid in their mouth. This is when glucagon is needed.
Glucagon is a hormone that signals the liver to release stored sugar into the bloodstream. It’s available by prescription in several forms. Newer versions are much simpler to use than older kits that required mixing powder with liquid. A nasal spray version works like a nasal decongestant: you insert the tip into one nostril and press the plunger. Pre-filled auto-injectors work similarly to an EpiPen, delivering the dose through the skin without any mixing or preparation. If you live with someone who uses insulin, having one of these on hand and knowing how to use it before an emergency happens can be lifesaving.
Low Blood Sugar Without Diabetes
Low blood sugar doesn’t only affect people with diabetes. Reactive hypoglycemia causes blood sugar to drop a few hours after eating, typically in people without diabetes. The exact cause often isn’t clear, though it can be linked to alcohol consumption, prior bariatric surgery, or rare metabolic conditions.
The immediate treatment is the same: fast-acting carbohydrates followed by a balanced snack. But the prevention strategy looks different. Rather than adjusting insulin doses, people with reactive hypoglycemia benefit from dietary changes that keep blood sugar more stable throughout the day. Eating several smaller meals about three hours apart, choosing high-fiber foods like whole grains and vegetables, and avoiding sugary foods or processed simple carbohydrates on an empty stomach all help smooth out blood sugar swings. If you drink alcohol, eating food alongside it reduces the chance of a drop.
Why Some People Stop Feeling Symptoms
People who experience frequent low blood sugar episodes can develop a condition where their body stops sending the usual warning signals. This happens because repeated lows essentially retrain the brain’s glucose-sensing system. Over time, the nervous system dials down its alarm response, so the sweating, shakiness, and hunger that normally alert you to falling blood sugar become muted or disappear entirely. Without those early warnings, blood sugar can drop to dangerous levels before you realize anything is wrong.
This creates a vicious cycle: the more lows you have, the harder they become to detect, which leads to more severe lows. The primary strategy for reversing this is to carefully avoid low blood sugar episodes for a period of weeks. As the brain goes longer without experiencing lows, its sensitivity to dropping glucose levels gradually returns. Structured education programs that focus on recognizing subtle symptoms, adjusting behavior around meals and insulin timing, and using continuous glucose monitors to catch lows early have all shown effectiveness in helping people regain awareness. If you’ve noticed that you no longer feel your lows, working with your care team to adjust your blood sugar targets upward temporarily can help reset your body’s warning system.