Blood sugar below 70 mg/dL is considered low, and raising it quickly requires fast-acting carbohydrates. The standard approach is called the 15-15 rule: eat or drink 15 grams of simple carbs, wait 15 minutes, then recheck your blood sugar. If it’s still under 70 mg/dL, repeat the process. Most mild to moderate episodes resolve within one or two rounds.
Recognizing Low Blood Sugar
Your body sends warning signals in a predictable sequence when blood sugar drops. The earliest symptoms come from your nervous system revving up: sweating, a racing heart, shaky hands, anxiety, and sudden intense hunger. These adrenaline-driven signs act as an early alarm, giving you a window to act before things get worse.
If blood sugar continues to fall, the brain starts running short on fuel. That’s when cognitive symptoms appear: confusion, difficulty concentrating, irritability, slurred speech, and trouble walking straight. Below 54 mg/dL is classified as severely low, and at that point a person can lose consciousness or have a seizure. The goal is to catch and correct a drop while you’re still in the shaky, sweaty, hungry stage.
The 15-15 Rule: Step by Step
The 15-15 rule is the go-to method recommended by the CDC for treating mild to moderate low blood sugar. Here’s how it works:
- Eat or drink 15 grams of fast-acting carbohydrates. These are simple sugars your body absorbs quickly.
- Wait 15 minutes. Give the sugar time to enter your bloodstream.
- Recheck your blood sugar. If it’s still below 70 mg/dL, have another 15 grams and wait again.
The key is using the right amount. Too little won’t bring your levels up fast enough, and too much can send blood sugar swinging high. Stick close to 15 grams per round.
Best Fast-Acting Foods and Portions
Not all sugary foods hit your bloodstream at the same speed. You want simple carbohydrates with little or no fat, protein, or fiber slowing them down. Here are specific portions that deliver roughly 15 grams of carbs:
- Fruit juice or regular soda: half a cup (4 ounces)
- Honey: 1 tablespoon (about 17 grams of carbs)
- Glucose tablets: follow the package directions, typically 3 to 4 tablets
- Skittles: 15 pieces
- Jelly beans (Jelly Belly): 15 pieces
- Gummy bears: 7 pieces
- Fruit gummy snack pouch (0.8 oz): one pouch (about 17 grams of carbs)
- Starburst chews: 4 pieces
Glucose tablets are the most precise option because they’re dosed specifically for this purpose. Juice boxes in 4-ounce sizes are another convenient choice, especially for keeping in a bag or bedside drawer. Avoid chocolate, peanut butter cups, or ice cream for a quick fix. The fat in those foods slows digestion and delays the sugar from reaching your blood when you need it most.
What Happens Inside Your Body
Your liver is the main player in blood sugar regulation. It stores glucose in a packed-together form called glycogen, like a reserve fuel tank. When blood sugar drops, your pancreas releases a hormone called glucagon, which signals the liver to convert that stored glycogen back into glucose and release it into your bloodstream.
Glucagon also prevents the liver from absorbing and storing more glucose, keeping what’s already circulating available for your brain and muscles. During longer periods without food, the liver can even manufacture new glucose from non-carbohydrate sources like amino acids and fats. This backup system is why most people can skip a meal without fainting, but it has limits, especially for people on insulin or certain diabetes medications that can override these natural safety mechanisms.
Keeping Blood Sugar Stable After a Low
Correcting a low is only half the job. Once your blood sugar is back above 70 mg/dL, you need to keep it there. If your next meal is more than an hour away, eat a small snack that combines carbohydrates with protein or fat. Protein is roughly three times more effective than fat at moderating how quickly glucose enters and leaves your bloodstream, so prioritize protein-rich pairings.
Good options include crackers with cheese, an apple with peanut butter, a handful of trail mix, or a small turkey sandwich. The carbohydrate provides a continued source of glucose while the protein slows its absorption, preventing another crash. This pairing strategy also works as a daily habit. Eating balanced meals and snacks throughout the day, rather than relying on carbs alone, reduces the frequency of blood sugar swings in the first place.
Severe Lows: When Someone Can’t Treat Themselves
If a person is unconscious, seizing, or too confused to swallow safely, do not try to put food or liquid in their mouth. This is when glucagon, a prescription emergency medication, becomes essential. Glucagon works by forcing the liver to dump its stored glucose into the bloodstream, and it can raise blood sugar within about 10 minutes.
Several forms are available by prescription:
- Nasal spray: A dry powder sprayed into one nostril. No inhalation needed. Approved for ages 4 and up.
- Auto-injector pen: A pre-filled, single-use device similar to an EpiPen. Approved for ages 2 and up.
- Pre-filled syringe: Ready to inject without mixing.
- Emergency kit: Contains a vial of glucagon powder and a syringe that require mixing before injection.
If you take insulin or medications that can cause severe lows, keep glucagon accessible at home and at work. Make sure someone close to you, a partner, coworker, or roommate, knows where it is and how to use it. The nasal spray and auto-injector are the simplest for bystanders with no medical training.
Low Blood Sugar Without Diabetes
People who don’t have diabetes can also experience low blood sugar, a condition sometimes called reactive hypoglycemia. It often happens two to four hours after eating, particularly after meals heavy in refined carbohydrates. The body overproduces insulin in response to the sugar load, and blood glucose drops below normal once the food is digested.
For non-diabetic low blood sugar, the treatment approach shifts toward finding and addressing the root cause rather than just correcting individual episodes. Dietary changes are the first line of defense: eating smaller, more frequent meals that are high in protein and fiber while keeping refined carbohydrates low. Some people benefit from avoiding liquids during meals, which slows the rate at which food leaves the stomach.
Other causes of non-diabetic hypoglycemia include certain medications, excessive alcohol intake, hormonal deficiencies, and rare conditions like insulin-producing tumors. If you’re experiencing repeated episodes of low blood sugar and you don’t take diabetes medication, the pattern itself is worth investigating rather than simply treating each drop as it comes.