What to Give a Diabetic When Sugar Is Low

Fast-acting carbohydrates are the first-line treatment when a person with diabetes has low blood sugar. Glucose tablets, fruit juice, regular soda, or table sugar dissolved in water all work because they deliver simple sugars into the bloodstream quickly. The standard recommendation is roughly 15 to 20 grams of fast-acting carbohydrate, followed by a recheck of blood glucose after 15 minutes. That simple formula handles most mild episodes, but the picture gets more complicated when the person cannot swallow, when the low happens during sleep or exercise, or when panic leads to overtreatment and a spike afterward.

Which Foods and Drinks Work Fastest

The goal is to raise blood glucose quickly without a lot of extra fat, protein, or fiber slowing things down. Fat delays stomach emptying, so a chocolate bar or peanut butter crackers are poor first choices even though they contain sugar. The sugar locked inside a fatty food takes longer to reach the bloodstream, which is the opposite of what you want in an emergency. Stick with options that are almost pure simple carbohydrate:

Glucose tablets: Sold over the counter, pre-measured so you know exactly how many grams you are getting.
Fruit juice: About 120 mL (four ounces) of orange or apple juice delivers roughly 15 grams of carbohydrate.
Regular soda: Half a standard can, not diet.
Hard candy: A few pieces of something like jelly beans or gummy bears. Avoid chocolate-coated varieties.
Table sugar or honey: A tablespoon dissolved in water or placed directly under the tongue.

Diet drinks, sugar-free candy, and artificially sweetened anything will do nothing for a low. Make sure whatever you grab is the full-sugar version.

How Much Carbohydrate Is Enough

The widely taught “15-15 rule” says to take 15 grams of carbohydrate, wait 15 minutes, then recheck. A systematic review of oral carbohydrate treatment for hypoglycemia in people with type 2 diabetes found near-complete resolution of mild lows with 15 grams at a 30-minute recheck. The same review noted that a larger 30-gram dose resolved lows faster, within about 10 minutes, but came with a meaningful risk of rebound high blood sugar afterward.¹

That trade-off is worth understanding. Doubling the dose does speed things up, but you may end up with blood sugar well above 180 mg/dL an hour or two later, which creates its own problems. For most mild episodes where the person is alert and able to eat, 15 grams is the safer starting point. If blood sugar is still low at the 15-minute recheck, repeat with another 15 grams.

When the Person Cannot Eat or Is Unconscious

If someone with diabetes is confused, seizing, or has passed out, do not try to put food or liquid in their mouth. The choking risk is real. This is where glucagon comes in. Glucagon is a hormone that signals the liver to release stored glucose, and it works even when the person cannot swallow.

The traditional glucagon emergency kit requires mixing a powder with a liquid before injecting it into the thigh or abdomen. For adults and children over roughly 25 kilograms, the standard dose is 1 milligram; for smaller children, half that amount is recommended.² The mixing step can feel stressful in an emergency, so newer options have simplified the process considerably.

A ready-to-use liquid glucagon autoinjector was tested head-to-head against the traditional kit in a crossover trial of 80 adults with type 1 diabetes. Both rescued every participant from severe hypoglycemia without additional measures.³ Nasal glucagon, delivered as a dry powder sprayed into one nostril, is another option that requires no injection at all.⁴ The person does not need to inhale; the powder is absorbed through the nasal lining. For a bystander with shaking hands and no medical training, the nasal or autoinjector forms remove the mixing and needle steps that make the traditional kit intimidating.

After giving glucagon, turn the person on their side in case they vomit, and call emergency services. Most people regain consciousness within 10 to 15 minutes. Once they are alert enough to swallow, offer a follow-up snack with both carbohydrate and protein to stabilize blood sugar while the glucagon wears off.

Placing Sugar Under the Tongue

There is a middle ground between “fully conscious and able to eat” and “completely unconscious.” Sometimes a person is groggy, uncooperative, or nauseated but not passed out. In that scenario, placing granulated sugar or a glucose gel under the tongue or against the inside of the cheek can get some glucose absorbed through the mouth’s mucous membranes without requiring the person to actively chew and swallow.

A Cochrane review of first-aid glucose routes found that sublingual administration of table sugar raised blood glucose more than the oral route in a small study of children who were hypoglycemic and also sick with malaria or a respiratory infection. The difference was about 17 mg/dL at the 20-minute mark.⁵ The evidence base is thin and comes from a very specific population, so this should not replace glucagon for someone who is truly unconscious. But for a semi-conscious person who can keep sugar under their tongue without choking, it is a reasonable bridge while you prepare glucagon or wait for help.

The Overtreatment Trap

Panic is the enemy of good treatment. When blood sugar is dropping and the person feels shaky, sweaty, and confused, the instinct is to eat everything in the refrigerator. That instinct reliably produces a blood sugar roller coaster: a low followed by a spike well above 180 mg/dL, followed sometimes by another correction and another low. Researchers examining continuous glucose monitor data found that these rebound highs, defined as readings above 180 mg/dL starting within two hours of a low, were more frequent and lasted longer in people with highly variable glucose patterns.⁶

The practical takeaway: treat with a measured amount of fast-acting carbohydrate, then wait. Fifteen minutes feels like an eternity when your hands are trembling, but gobbling a second round of juice before the first one has had time to work is how you end up with a blood sugar of 250 an hour later. If you have treated and the number is still low at the 15-minute mark, take another 15 grams. Resist the urge to treat a feeling rather than a number.

When Illness Makes Eating Impossible

Stomach bugs create a particularly tricky situation for children with type 1 diabetes. Insulin is still working, food is not staying down, and blood sugar can fall fast. The standard advice to eat 15 grams of carbohydrate does not help much when a child is vomiting everything they try to drink. Mini-dose glucagon, given as a small subcutaneous injection, has been shown to be effective in preventing or managing hypoglycemia in children during gastroenteritis or periods when they simply cannot eat enough carbohydrate.⁷

The doses used in mini-dose protocols are much smaller than the full emergency dose. A parent or caregiver trained on the technique can give a tiny amount of glucagon to nudge blood sugar up just enough to keep it in a safe range without triggering a large spike. This is not something to improvise; it requires guidance from the child’s diabetes team ahead of time, including weight-based dosing instructions and clear thresholds for when to use it versus when to head to the emergency room.

Exercise and Dropping Blood Sugar

Physical activity increases how quickly muscles pull glucose out of the blood, so lows during or after exercise are common in people who use insulin. Prevention matters at least as much as treatment here. One approach studied in runners with type 1 diabetes combined a reduced insulin dose with a low-glycemic-index carbohydrate taken 30 minutes before exercise. That timing virtually eliminated hypoglycemia during a 45-minute run, while the same strategy applied two hours beforehand led to five hypoglycemic episodes out of seven participants.⁸

If blood sugar does drop during a workout, the same rules apply: stop exercising and take 15 to 20 grams of fast-acting carbohydrate. Wait for blood sugar to recover before resuming. Exercising through a low is dangerous because it keeps pulling glucose out of the blood while you are trying to put it back in.

Why Your CGM Might Not Catch a Low in Time

Continuous glucose monitors measure glucose in the fluid just under the skin, not directly in the blood. That fluid lags behind the bloodstream, and the lag matters most when glucose is changing quickly, exactly the situation during exercise or a fast drop. During prolonged aerobic exercise in adults with type 1 diabetes, the delay between what a fingerstick shows and what the CGM displays averaged about 12 minutes. During documented hypoglycemic episodes, the average fingerstick reading was 60 mg/dL while the CGM was still showing 81 mg/dL.⁹

That 20 mg/dL gap means a CGM might tell you your blood sugar is 80 and dropping when it is already at 60. If you feel symptoms of a low during exercise but your CGM still shows a borderline number, trust your body and treat. A confirmatory fingerstick, if you have a meter handy, is better than waiting for the CGM to catch up.

Nighttime Lows

Hypoglycemia during sleep is especially unnerving because the person may not wake up to feel the warning signs. A study evaluating a prediction-based bedtime snack intervention in adults with type 1 diabetes found that the intervention did not significantly reduce overnight lows below 70 mg/dL. However, when looking at more serious drops below 54 mg/dL lasting at least 10 minutes, the smart-snack arm showed a meaningful reduction, cutting those events by about a third compared to the control group.¹⁰

For people who experience frequent overnight lows, a bedtime snack containing both carbohydrate and protein or fat can help sustain blood sugar through the night. The carbohydrate raises it now; the protein and fat slow digestion and provide a more gradual release later. Common choices include a small handful of crackers with cheese, a glass of milk, or a slice of toast with peanut butter. The exact composition matters less than the principle: something that provides both immediate and sustained fuel. Adjusting basal insulin doses with the help of a care team is the longer-term fix, but a bedtime snack is a useful stopgap.

When Warning Signs Disappear

Some people with long-standing diabetes lose the ability to feel their blood sugar dropping. The sweating, shaking, and racing heart that normally alert you to a low simply stop happening, a condition called hypoglycemia unawareness. Without those warning signs, the first symptom can be confusion or loss of consciousness, leaving no window for the person to treat themselves. Managing this condition is complex and typically requires a coordinated effort involving the diabetes care team and structured patient education.¹¹

If you live with or care for someone who has hypoglycemia unawareness, preparedness shifts from “they will tell you when they need help” to “you may need to recognize it before they do.” Keep glucagon accessible and make sure everyone in the household knows where it is and how to use it. A CGM with low-glucose alerts is particularly valuable for this group, though as noted above, the lag means alerts may fire a few minutes behind reality.

Helping Someone Else Through a Low

Bystanders and caregivers often freeze during a severe low, and that hesitation is understandable. Research on parents of children with type 1 diabetes has documented how reluctant extended family members and babysitters can be to take responsibility for diabetes management. Caregivers in multiple studies reported that family members and potential babysitters refused to care for the child because they were afraid of making a mistake with insulin or not knowing how to handle a blood sugar emergency.¹²

The fix is not complicated, but it does require advance preparation. Anyone who regularly spends time with a person who uses insulin should know three things before an emergency happens:

Where the supplies are: Glucose tablets, juice boxes, and glucagon should be stored in a consistent, easy-to-find location.
How to use glucagon: A five-minute walkthrough with the nasal or autoinjector form is enough for most people. The traditional kit with powder and syringe takes more practice.
When to call 911: If the person is unconscious and glucagon is not available, or if they do not respond to glucagon within 15 minutes, emergency services need to be involved.

Having these conversations before an emergency removes the decision-making burden in the moment. A grandparent or babysitter who has physically held the nasal glucagon device and practiced the steps is far more likely to act quickly than one who is reading the instructions for the first time while a child is unresponsive on the floor.

What Happens at the Hospital

If someone arrives at an emergency room with severe hypoglycemia, the medical team will typically give intravenous dextrose, which is essentially glucose delivered straight into a vein. This raises blood sugar within minutes. Glucagon may also be given by injection if intravenous access is not immediately available. Once blood sugar stabilizes, the focus shifts to figuring out what caused the episode: Was it too much insulin? A missed meal? A new medication? An underlying change in kidney function that altered how the body processes insulin?

Hospital treatment is highly effective but rarely necessary for someone whose household is prepared with glucagon and fast-acting carbohydrates. Most mild and even moderate lows can be managed at home. The situations that genuinely require emergency care are prolonged unconsciousness, seizures, lows that do not respond to glucagon, or recurrent severe episodes that suggest something in the treatment plan needs to change.

Stocking a Low Blood Sugar Kit

Keeping a dedicated kit takes the guesswork out of a stressful moment. A small zippered pouch or container with the following covers nearly every scenario:

Glucose tablets or gel: Pre-measured, shelf-stable, and unlikely to be eaten as a casual snack.
Juice boxes: Single-serving boxes are portion-controlled and portable.
Glucagon: Nasal or autoinjector form if possible; the traditional kit if that is what insurance covers. Check the expiration date every few months.
A blood glucose meter and test strips: Useful for confirming a low, especially when CGM readings seem off.
A written action plan: A simple card with steps for a mild low, steps for a severe low, and the person’s emergency contact and doctor’s number.

Keep a kit at home, one in the car, and one at school or work. Replace items as they expire or get used. The cost of maintaining these kits is trivial compared to a single ambulance ride, and the peace of mind they provide to both the person with diabetes and the people around them is hard to overstate.