Hypoglycemia is treated by raising blood sugar quickly with fast-acting carbohydrates, following what’s known as the 15-15 rule: eat or drink 15 grams of carbs, wait 15 minutes, then recheck your blood sugar. For severe episodes where a person can’t eat or drink, emergency glucagon is the go-to treatment. Beyond the immediate fix, preventing future lows requires adjustments to medication, diet, or both.
Understanding the Severity Levels
Not all low blood sugar episodes are the same, and the treatment approach depends on how far your glucose has dropped. The American Diabetes Association defines three levels. Level 1 is a blood sugar below 70 mg/dL but at or above 54 mg/dL. You’ll likely feel shaky, sweaty, or irritable, but you can treat it yourself. Level 2 is below 54 mg/dL, which is clinically significant and needs immediate action. Level 3 is any episode severe enough that you need someone else’s help to recover, regardless of the number on the meter. This might mean confusion, seizures, or loss of consciousness.
The 15-15 Rule for Mild to Moderate Lows
If you can still eat and drink, the standard approach is straightforward. Consume 15 to 20 grams of fast-acting carbohydrates, wait 15 minutes, and test again. If your blood sugar is still below 70 mg/dL, repeat. Once it comes back up, eat a small meal or snack to keep it stable.
The key is choosing carbs that absorb quickly. Good options include:
- Glucose tablets: four tablets provide roughly 15 grams
- Fruit juice: half a cup (4 ounces) of regular juice, not low-calorie or reduced-sugar versions
- Sugar, honey, or corn syrup: 1 tablespoon
What you don’t want is something high in fat or protein, like a candy bar or peanut butter. Fat slows digestion, which delays the glucose from reaching your bloodstream when you need it fast. Save the protein and fat for the follow-up snack after your blood sugar has recovered.
Emergency Glucagon for Severe Episodes
When someone with low blood sugar is unconscious, confused, or unable to swallow, putting food or liquid in their mouth is a choking risk. This is where glucagon comes in. Glucagon is a hormone that signals the liver to release stored glucose into the bloodstream, and it’s available in several forms that don’t require medical training to use.
A nasal spray delivers a single 3 mg dose through one nostril, no injection needed. Pre-filled auto-injectors work similarly to epinephrine pens and are injected into the thigh. There’s also a traditional emergency kit that contains a powder you mix with sterile water before injecting, though the newer options are faster to prepare in a crisis. If you take insulin or medications that can cause severe lows, having one of these on hand and making sure the people around you know where it is and how to use it can be lifesaving.
What Happens at the Hospital
If glucagon isn’t available or doesn’t work, or if severe hypoglycemia leads to a trip to the emergency room, medical teams use intravenous sugar solutions to bring blood glucose up rapidly. They administer concentrated glucose in small, controlled doses up to a maximum of 25 grams, monitoring levels closely to avoid overcorrecting. Once blood sugar stabilizes, the focus shifts to figuring out what caused the episode and adjusting the treatment plan to prevent it from happening again.
Adjusting Insulin to Prevent Future Lows
For people on insulin, recurring hypoglycemia usually means the dose is too high relative to what the body needs at that moment. The general approach is a 20% reduction in the total daily insulin dose after any episode where blood sugar drops below 70 mg/dL. For borderline situations, where pre-meal readings fall between 70 and 100 mg/dL in someone with risk factors like reduced kidney function, poor appetite, or older age, a 10 to 20% reduction is typically enough to prevent an outright low.
These adjustments aren’t one-size-fits-all. Your insulin needs shift based on activity level, what you eat, stress, illness, and dozens of other factors. The goal is to find the dose that keeps blood sugar in range without dipping too low, which often takes some trial and error with your care team.
How Insulin Pumps Help Prevent Lows Automatically
Continuous glucose monitors paired with insulin pumps have introduced a technology called predictive low-glucose suspend. The system reads your glucose level every few minutes and uses the last four readings to predict where your blood sugar will be 30 minutes from now. If it predicts a drop below 80 mg/dL, or if your current reading is already below 70, the pump automatically stops delivering insulin.
Once your glucose starts rising again or is no longer predicted to drop, insulin delivery resumes on its own. There’s also a safety limit: if insulin has been suspended for 120 minutes within any 150-minute window, delivery restarts regardless. This technology doesn’t eliminate lows entirely, but it catches many episodes before they become symptomatic, especially overnight when you can’t feel the warning signs.
Treating Hypoglycemia in Non-Diabetics
Low blood sugar doesn’t only affect people with diabetes. Reactive hypoglycemia, where blood sugar drops after eating rather than from medication, requires a different management strategy centered on diet rather than emergency carbs.
The core dietary approach is eating smaller, more frequent meals that are high in protein and fiber and low in simple carbohydrates, keeping carbs under about 30 grams per meal and choosing complex carbs over refined sugars. Separating liquids from solid food at meals also helps slow digestion and prevent the rapid blood sugar spike and crash cycle. Some people benefit from adding uncooked cornstarch to meals, which acts as a slow-release glucose source because it takes longer to break down.
When a low does occur with reactive hypoglycemia, the correction strategy differs slightly from the standard 15-15 rule. Instead of treating with carbs alone, the recommendation is to consume 10 to 15 grams of simple sugar to bring levels up quickly, then immediately follow with a source of protein or fat, like a cheese stick or spoonful of peanut butter. This prevents the “yo-yo” pattern where correcting a low with pure sugar triggers another insulin surge and another crash shortly after.
People who develop hypoglycemia after bariatric surgery face a similar pattern, where meals cause an exaggerated insulin response. The same dietary principles apply: mixed meals, high protein, low simple carbs, and no drinking with eating. For rarer conditions like certain glycogen storage diseases, management focuses on avoiding fasting, eating frequent protein-rich meals, and using uncooked cornstarch to maintain steady glucose levels between meals.