The fastest way to raise low blood sugar is to eat 15 grams of fast-acting carbohydrates, wait 15 minutes, and recheck. This approach, known as the 15/15 rule, is the standard method recommended by medical guidelines. Glucose tablets are the most precise option, but fruit juice, regular soda, or candy work too.
The 15/15 Rule
Eat or drink 15 grams of a fast-acting carbohydrate. Wait 15 minutes for it to enter your bloodstream, then check your blood sugar again. If it’s still low, repeat with another 15 grams. The goal is a controlled rise rather than overcorrecting into high blood sugar, which is a common mistake when people panic and eat everything in sight.
Portions that provide roughly 15 grams of fast-acting carbs include:
- 3 to 4 glucose tablets
- 4 ounces (half a cup) of fruit juice
- 4 ounces of regular soda (not diet)
- 1 tablespoon of honey or sugar
- A small handful of jelly beans or hard candy
Avoid foods with fat in them for this initial correction. Chocolate, peanut butter, or ice cream slow digestion and delay the sugar from reaching your blood. Save those for the follow-up step.
What to Eat After Your Sugar Stabilizes
Once your blood sugar comes back up, you need to keep it there. A small snack combining about 15 grams of carbohydrate with some protein prevents a secondary drop. Without this step, your blood sugar can slide right back down, especially if your next meal is more than an hour away.
Good stabilizing snacks 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 an ounce of cheese
- 6 saltine crackers with a quarter cup of tuna salad
- 55 Goldfish crackers with an ounce of cheese
- 3 cups of plain popcorn with an ounce of nuts
The protein slows the digestion of the carbohydrate, giving you a longer, more gradual energy release instead of another spike and crash.
Recognizing Low Blood Sugar
Your body sends two waves of warning signals when blood sugar drops. The first wave comes from your nervous system reacting to the change: shakiness, a pounding heart, sweating, sudden hunger, anxiety, and tingling in your lips or fingers. These are your early alerts.
If blood sugar keeps falling, a second set of symptoms appears as your brain starts running short on fuel: confusion, difficulty concentrating, weakness, fatigue, a sensation of warmth, and in severe cases, slurred speech or loss of consciousness. By the time these show up, you need to act immediately or have someone help you.
Some people, particularly those with diabetes who experience frequent lows, can develop a condition where the early warning signs fade over time. Their body stops sounding the alarm at the usual threshold, so the first symptom they notice may already be confusion or impaired thinking. This makes severe episodes more likely and increases the risk of accidents and injuries. If you’ve noticed your warning signs becoming less reliable, that’s something worth discussing with your care team, as there are strategies to help restore your body’s awareness.
When Someone Else Needs to Step In
If blood sugar drops so low that a person can’t swallow safely or loses consciousness, do not try to put food or liquid in their mouth. This is when emergency glucagon is used. Glucagon is a hormone that signals the liver to release stored sugar into the bloodstream, and it comes in several forms designed for bystanders to administer.
A nasal powder version works by inserting a tip into one nostril and pressing a plunger. The person doesn’t need to inhale. An auto-injector version works similarly to an EpiPen, injecting into the thigh, abdomen, or upper arm when pressed against the body. Blood sugar typically starts rising within about 10 minutes. If there’s no response within 15 minutes, a second dose from a new device can be given.
If you’re at risk for severe lows, keep glucagon accessible and make sure the people around you know where it is and how to use it.
Preventing Lows During Exercise
Physical activity pulls sugar out of your bloodstream for energy, which is why exercise is one of the most common triggers for low blood sugar. The risk is highest during moderate-intensity exercise lasting longer than 30 minutes. Short bursts of high-intensity work like weight training or interval sessions typically don’t cause the same drop.
For longer workouts, consuming 0.5 to 1 gram of carbohydrate per kilogram of body weight for every hour of exercise helps keep levels stable. For a 150-pound person, that works out to roughly 35 to 70 grams per hour. If your blood sugar is below 90 mg/dL before you start, eating 10 to 30 grams of quick-absorbing carbs beforehand is a reasonable precaution.
Timing matters too. Exercise-induced lows can happen not just during activity but up to 48 hours afterward. Evening workouts carry extra risk because a delayed drop can hit while you’re sleeping and unable to notice symptoms. If you do exercise late in the day, check your blood sugar before bed and avoid pushing yourself to exhaustion.
Preventing Lows Overnight
Nocturnal hypoglycemia is particularly risky because you can sleep right through your body’s warning signs. Research in Diabetes Care found that a bedtime snack containing both carbohydrate and protein eliminated overnight lows entirely, even when blood sugar at bedtime was only moderately elevated.
The findings broke down by bedtime blood sugar level. If your reading is above 180 mg/dL (10 mmol/l), no snack is typically necessary. Between 126 and 180 mg/dL, any snack helps. Below 126 mg/dL, a snack with protein is specifically recommended. Without a snack, 71% of overnight low episodes occurred in study participants. Any of the carb-plus-protein snack combinations listed earlier work well as a bedtime option.
Why Blood Sugar Drops in Non-Diabetic People
Low blood sugar doesn’t only happen to people with diabetes. If you don’t have diabetes and still experience crashes, there are two broad patterns. Reactive hypoglycemia happens a few hours after eating, often after a high-carb meal, when your body overshoots its insulin response. Fasting hypoglycemia happens when you haven’t eaten for an extended period.
Alcohol is one of the most common non-diabetes causes because it blocks the liver’s ability to release stored sugar. Other causes include liver or kidney problems, adrenal or pituitary gland disorders, severe illness, and certain medications like some antibiotics and blood pressure drugs. Bariatric surgery, particularly gastric bypass, is also a well-recognized trigger because it changes how quickly food enters the small intestine.
If you’re experiencing repeated episodes of low blood sugar without an obvious explanation, the pattern itself is a clue worth investigating. Occasional mild dips after skipping a meal are common and usually harmless, but frequent or severe episodes can point to an underlying condition that needs attention.