When your blood sugar drops below 70 mg/dL (3.9 mmol/L), you need fast-acting carbohydrates to bring it back up. The standard approach is called the 15-15 rule: eat or drink 15 grams of quick carbs, wait 15 minutes, then recheck. Most mild episodes resolve within one or two rounds of this cycle, but drops below 54 mg/dL can become emergencies requiring outside help.
Recognizing the Symptoms
Low blood sugar typically announces itself before it becomes dangerous. Early signs include shakiness, sweating, a fast heartbeat, and sudden hunger. You might feel irritable or anxious without an obvious reason. These symptoms are your body’s warning system, and acting on them quickly keeps the episode from escalating.
As blood sugar continues to fall, symptoms shift from uncomfortable to alarming. Weakness, blurred vision, confusion, and strange behavior all signal a more serious drop. Seizures and loss of consciousness can follow if levels keep declining. A reading below 54 mg/dL is considered severe, and at that point you may not be able to treat yourself.
The 15-15 Rule
This is the go-to method for treating mild to moderate low blood sugar. Eat or drink something that provides 15 grams of fast-acting carbohydrates. Wait 15 minutes, then check your blood sugar again. If it’s still under 70 mg/dL, repeat with another 15 grams. Keep cycling through these steps until your reading is back in your target range.
The key word is “fast-acting.” You want carbs that hit your bloodstream quickly, not foods with fat or fiber that slow digestion. Good options that deliver roughly 15 grams include:
- Glucose tablets: 3 to 4 tablets, depending on the brand (check the label)
- Fruit juice: half a cup of unsweetened juice
- Hard candy: about 3 pieces
- Regular soda: half a cup (not diet)
- Honey or sugar: about 1 tablespoon
Glucose tablets are the most precise option because they’re pre-measured, and they won’t tempt you to overtreat. Overtreating is a common mistake. When you feel shaky and desperate, it’s natural to grab a whole glass of juice or a handful of candy. But flooding your system with too many carbs can send blood sugar rocketing in the other direction. Stick to 15 grams and wait the full 15 minutes, even when every instinct tells you to eat more.
What to Eat After Your Levels Recover
Once your blood sugar is back above 70 mg/dL, the job isn’t done. Fast-acting carbs wear off quickly, and without a follow-up, your levels can drop right back down. Eat a balanced snack or small meal that combines protein with longer-lasting carbohydrates. A handful of crackers with peanut butter, a cheese sandwich, or yogurt with fruit all work well. The protein and complex carbs provide a slower, steadier release of energy that keeps your blood sugar stable while you figure out what caused the drop in the first place.
Treating Severe Low Blood Sugar
If someone with low blood sugar is confused, unable to eat, or unconscious, do not try to put food or liquid in their mouth. They could choke. This is when glucagon becomes essential. Glucagon is a hormone that signals the liver to release stored sugar into the bloodstream, and it comes in several forms designed for emergency use by non-medical people.
A nasal spray version is the simplest. It requires one step: insert the tip into a nostril and press the plunger. No needles, no mixing, and it works even on someone who is unconscious. A pre-mixed injectable pen works like an EpiPen. You remove the cap, press the needle into the outer thigh, upper arm, or lower stomach at a 90-degree angle, and inject. A third type requires mixing a powder with a liquid before injecting into a muscle, which makes it trickier to use under pressure.
Regardless of the type, turn an unconscious person on their side after giving glucagon. Vomiting is a common side effect, and this position prevents choking. If no glucagon kit is available, or if you don’t know how to use one, call emergency services immediately.
When It Becomes an Emergency
Call 911 or your local emergency number if someone with low blood sugar has a seizure, loses consciousness, or doesn’t improve after glucagon. Also call if you find someone confused and disoriented and you have no way to check their blood sugar or administer glucagon. Time matters during severe episodes because prolonged low blood sugar can cause lasting harm.
If you take insulin or medications that lower blood sugar, talk with the people around you, whether that’s family, coworkers, or close friends. They should know where you keep your glucagon, how to use it, and when to call for help. Practicing with an expired or training kit takes less than five minutes and removes the panic of figuring it out for the first time during a real emergency.
Preventing Repeat Episodes
A single low blood sugar episode is worth paying attention to. Repeated episodes mean something in your routine needs adjusting. Common triggers include skipping meals, exercising more intensely than usual, taking too much insulin, or drinking alcohol without eating. Keeping a log of when lows happen, what you ate before, and what you were doing can reveal patterns that are hard to spot otherwise.
Carrying glucose tablets or a small juice box wherever you go is a simple habit that turns a potential crisis into a minor inconvenience. If you use insulin, wearing a medical ID bracelet gives bystanders critical information if you’re ever unable to speak for yourself. Low blood sugar is manageable when you catch it early, treat it precisely, and follow up to prevent the next one.