The fastest way to raise low blood sugar is to eat or drink 15 grams of fast-acting carbohydrates, then wait 15 minutes and check again. Blood sugar below 70 mg/dL is considered low, and getting it back up quickly matters because your brain depends on a steady supply of glucose to function normally.
The 15-15 Rule
This is the standard approach recommended by major health organizations, and it works well for mild to moderate low blood sugar. Eat 15 grams of fast-acting carbohydrates, wait 15 minutes, then recheck your blood sugar. If it’s still below 70 mg/dL, eat another 15 grams and wait again. Keep repeating until your blood sugar is back in your target range.
The reason you eat only 15 grams at a time, rather than raiding the pantry, is that overcorrecting can send your blood sugar too high. It’s tempting to keep eating when you feel shaky and awful, but giving your body 15 minutes to absorb the sugar prevents that roller coaster.
What to Eat or Drink Right Now
You want simple sugars that hit your bloodstream fast. These are not the foods you’d normally choose for a balanced diet, and that’s the point. Reach for:
- Glucose tablets or gel: the most precise option since they come in measured doses
- 4 ounces (half a cup) of fruit juice: orange juice or apple juice work well
- 4 ounces of regular soda: not diet, which has no sugar
- A tablespoon of honey or sugar dissolved in water
- A few pieces of hard candy: check the label for about 15 grams of sugar
Avoid foods with fat or protein for this first step. A candy bar or peanut butter crackers will raise your blood sugar eventually, but the fat slows digestion and delays the glucose from reaching your bloodstream. Save those for the follow-up step.
Keep Your Blood Sugar Stable Afterward
Once your blood sugar is back above 70 mg/dL, you’re not done. Fast-acting sugar burns through quickly, and without a follow-up snack, your levels can drop right back down. Eat a small meal or snack that includes both protein and a slow-releasing carbohydrate. If your next meal is coming soon, go ahead and eat it, making sure it includes something starchy like bread, rice, pasta, or potatoes.
Good follow-up snack options that provide 15 to 20 grams of slower-releasing carbohydrates include a slice of toast, a small banana, a cereal bar, two oat biscuits, or a glass of milk (about 10 ounces). Pairing any of these with a source of protein, like cheese or a handful of nuts, helps keep your blood sugar from dipping again.
How to Recognize Low Blood Sugar
Mild to moderate low blood sugar typically causes shakiness, sudden hunger, dizziness, a fast or irregular heartbeat, headache, irritability, and difficulty concentrating. You might feel jittery for no obvious reason, or notice that you can’t see or speak as clearly as normal. These symptoms come on relatively fast and tend to get worse the longer your blood sugar stays low.
Severe low blood sugar, defined as below 54 mg/dL, is a different situation entirely. At that level, your brain isn’t getting enough fuel to function properly, and you may lose consciousness or have a seizure. If someone with low blood sugar is confused, unresponsive, or having a seizure, they should not be given food or drink because of the choking risk. This is when emergency glucagon is needed.
Low blood sugar can also happen during sleep. Signs include night sweats heavy enough to soak your pajamas or sheets, nightmares, and waking up feeling unusually tired, confused, or irritable. If you notice this pattern, it’s worth checking your blood sugar before bed and talking with your care team about prevention.
When Someone Can’t Eat or Drink
If a person is too disoriented or unconscious to safely swallow, oral sugar is not an option. Glucagon, a hormone that signals the liver to release stored glucose, can be given by someone nearby. It now comes in a nasal spray that’s straightforward to administer: you simply spray it into one nostril. Injectable versions also exist but require mixing before use, which can be stressful in an emergency. If you take insulin or medications that lower blood sugar, keeping glucagon accessible and making sure someone close to you knows where it is and how to use it can be lifesaving.
Why Blood Sugar Drops in the First Place
For people with diabetes, the most common triggers are taking too much insulin, delaying or skipping a meal, or exercising more intensely than usual. Physical activity makes your body more sensitive to insulin, and that effect can last for hours afterward, including overnight while you sleep. A hard workout in the afternoon can cause a low in the middle of the night.
Alcohol also increases the risk. Your liver normally releases glucose to keep blood sugar steady, but when it’s busy processing alcohol, that backup system slows down. Eating food when drinking helps offset this.
Changes in routine are another trigger. A new work schedule, travel across time zones, a different insulin regimen, or a sudden increase in activity can all shift the balance. Checking your blood sugar more frequently during transitions gives you a better picture of how your body is responding.
Preventing Repeated Lows
If low blood sugar keeps happening, the pattern itself becomes a problem. Repeated episodes can cause a condition where your body stops producing the early warning symptoms, like shakiness and hunger, that normally alert you to a drop. Without those signals, your blood sugar can fall dangerously low before you realize anything is wrong. This affects people who take insulin or certain oral diabetes medications.
The good news is that this blunted warning system can be reversed. Research shows that carefully avoiding lows for a period of time can reset your body’s ability to feel symptoms again. A continuous glucose monitor can be especially helpful here, since it tracks your levels around the clock and sends an alert when you’re trending low, catching drops you might otherwise miss.
Practical steps that reduce the frequency of lows include having a snack before bed on days when you’ve been very active, keeping fast-acting carbohydrates in your car and bag at all times, and always knowing your blood sugar level before driving. These small habits make a measurable difference over time.