--- title: "Low blood sugar: signs, the 15-15 rule, glucose tablets" description: "Below 70 mg/dL is low with diabetes. The CDC's 15-15 rule, how many glucose tablets to take, the signs, the causes, and when to call 911." canonical: https://glucosebench.com/low-blood-sugar alternate_html: https://glucosebench.com/low-blood-sugar language: en-US last_updated: 2026-09-27 type: guia --- # Low blood sugar (hypoglycemia): what to do in the first 15 minutes 1. [Home](https://glucosebench.com/) 2. [Blood sugar basics](https://glucosebench.com/blood-sugar) 3. Low blood sugar (hypoglycemia): what to do in the first 15 minutes A low can go from shaky to serious fast, so the part you need right now comes first. Then why lows happen, including one situation that matters if you take a blood sugar supplement with diabetes medication. By **GlucoseBench editorial team**Updated September 27, 2026 ![Low blood sugar (hypoglycemia): what to do in the first 15 minutes](https://glucosebench.com/img/guia-low-blood-sugar-640.webp) Short answer For most people with diabetes, blood sugar below 70 mg/dL is low, according to the CDC and the NIH; for people without diabetes, MedlinePlus says hypoglycemia is typically below 55 mg/dL. The CDC's fix is the 15-15 rule: have 15 grams of carbs, wait 15 minutes, check again, and repeat if you're still under 70 mg/dL. In glucose tablets, the CDC counts that as "3-4 glucose tablets", following the package. Severe low blood sugar, which the CDC puts below 54 mg/dL (below 55 on its treatment page), is an emergency: the NIDDK tells family and friends to call 911 right away after giving glucagon, or if there's no glucagon kit. No supplement is part of the fix: a low needs fast sugar, and a capsule marketed for blood sugar isn't that. ## The 15-15 rule, step by step 1. ### Check your number The NIDDK says to check as soon as you feel symptoms; MedlinePlus says to check if you think you're low, "even if you don't have symptoms." 2. ### Have 15 grams of carbs The CDC's first step: "Have 15 grams of carbs, then wait 15 minutes." The table below shows what that looks like. 3. ### Check again after 15 minutes "If it's still less than 70 mg/dL, repeat this process," the CDC says, and keep going until you're back in your target range. 4. ### Then eat properly Once you're back up, the CDC says to "eat a balanced snack or meal with protein and carbs." The NIDDK's version: if your next meal is more than 1 hour away, have a snack. ## What counts as 15 grams Speed is the point. The CDC says foods high in fiber (fruit, beans, lentils) or fat (chocolate, baked goods) "can slow down how fast you can absorb sugars." Option CDC (15 grams) NIDDK (15 to 20 grams) Glucose tablets "3-4 glucose tablets (follow instructions)" Four glucose tablets Glucose gel "1 dose of glucose gel (usually 1 tube; follow instructions)" One tube of glucose gel Juice 4 ounces (1/2 cup) 1/2 cup (4 ounces) of fruit juice, not low-calorie or reduced-sugar Soda 4 ounces (1/2 cup) of regular (non-diet) soda 1/2 can (4 to 6 ounces), not low-calorie or reduced-sugar Sugar, honey or syrup 1 tablespoon of sugar, honey, or syrup 1 tablespoon of sugar, honey, or corn syrup Hard candy, jellybeans, gumdrops See the food label for how much to eat Not listed Sources: CDC, "Treatment of Low Blood Sugar (Hypoglycemia)" (May 15, 2024); NIDDK, "Low Blood Glucose (Hypoglycemia)" (last reviewed July 2021). Both read on September 27, 2026. Both repeat after 15 minutes. On diabetes medicines that slow carb digestion, the NIDDK says only glucose tablets or gel work fast enough; with kidney disease, skip orange juice. Young children may need less than 15 grams (CDC). ## How a low feels, from mild to severe ### Early signs Fast heartbeat, shaking, sweating, nervousness or anxiety, irritability or confusion, dizziness and hunger (CDC). The NIDDK adds tiredness, headache and trouble seeing or speaking. MedlinePlus says they "tend to come on quickly." ### During sleep Crying out or nightmares, sweating enough to dampen your pajamas or sheets, and waking up tired, irritable or confused (NIDDK). An active day, late exercise, too much insulin or evening alcohol can set it up (CDC). ### Severe Weakness, trouble walking or seeing clearly, acting strange, seizures. The CDC says blood sugar this low "may make you faint (pass out)." ### No warning at all Hypoglycemia unawareness. More likely after more than 5 to 10 years of diabetes, with frequent lows, or on beta blockers, says the CDC, whose answer is checking more often, above all before driving. ## When to call 911 The CDC's page on low blood sugar puts severe lows "below 54 mg/dL"; its page on what to do says "below 55 mg/dL." Either way, the CDC says you may not be able to fix it with the 15-15 rule, or by yourself. MedlinePlus spells out the stakes: severe hypoglycemia "can cause serious complications, including passing out, coma, or even death." Glucagon, a prescription hormone that raises blood sugar fast, is what the NIDDK and the CDC name for a severe low. The NIDDK asks you to teach family, friends and coworkers how to give it, and to "call 911 right away after giving you glucagon or if you don't have a glucagon emergency kit with you." The CDC adds: "Contact a doctor for emergency medical treatment immediately after a glucagon injection." Food and drink come after that, and only on the CDC's condition: "If the person is awake and able to swallow," give a fast-acting sugar such as regular soda or fruit juice, then a longer-lasting carb with protein, like crackers and cheese. If they haven't woken up within 15 minutes of the injection, the CDC says they should get one more dose. ## Why blood sugar drops ### With diabetes Insulin and two kinds of diabetes pills, sulfonylureas and meglitinides (NIDDK). The CDC adds too few carbs for the insulin taken, exercise, alcohol, hot and humid weather and schedule changes. ### Without diabetes "Although it's rare, you can still get low blood glucose without having diabetes," says MedlinePlus: liver or kidney disease, hormone deficiencies, some weight-loss surgeries, and some medicines, such as certain heart medicines and antibiotics. It says to see your provider to find the cause. ## Blood sugar supplements and diabetes medication NCCIH, part of the NIH, warns that "using herbal supplements such as cinnamon, St. John's wort, or aloe with conventional diabetes drugs can cause unwanted side effects." Several labels reviewed on this site are marketed for blood sugar and list more than one such ingredient: Glyco Pulse and BloodArmor both name berberine, chromium, cassia cinnamon and bitter melon, and Insufend has 1 mg of chromium plus cassia cinnamon. BloodArmor's own FAQ tells people on blood sugar medication to "consult your doctor before use, as you may need to adjust your dosages to avoid low blood sugar." No public source we read has measured what these labels do alongside diabetes medicines, and we won't guess. The one herb where an NIH page mentions a drop in blood sugar is fenugreek ("Large doses may cause a harmful drop in blood sugar"), and none of these labels lists it. Any dose change is your doctor's call: "Do not make any changes to your medicines without talking to your doctor," the CDC says. Labels read on September 27, 2026; each product has a full review. ## Frequently asked questions **What are the symptoms of low blood sugar in adults?** Per the CDC: fast heartbeat, shaking, sweating, nervousness, irritability or confusion, dizziness and hunger. Signs differ between people, so learn your own. **How many glucose tablets should I take for low blood sugar?** The CDC lists 3-4 tablets as one serving for the 15-15 rule; the NIDDK's example is four tablets, for 15 to 20 grams. Follow the package, then wait 15 minutes and check again. **What causes low blood sugar if you don't have diabetes?** It's rare. MedlinePlus lists liver or kidney disease, hormone deficiencies, some weight-loss surgeries and some heart medicines and antibiotics, and puts the line typically below 55 mg/dL. See a doctor to find the cause. **When is low blood sugar an emergency?** When it's severe (the CDC says below 54 mg/dL on one page and below 55 mg/dL on another), when the person can't handle it alone, or when they pass out. Use glucagon if they have it; the NIDDK says to call 911 right after giving it, or right away if there's no kit. **Can a blood sugar supplement cause low blood sugar?** NCCIH warns that herbal supplements used with conventional diabetes drugs "can cause unwanted side effects," and BloodArmor's own FAQ tells buyers on blood sugar medication: "consult your doctor before use, as you may need to adjust your dosages to avoid low blood sugar." No public source we read has measured it for the labels on this site. On diabetes medication, ask your doctor before adding any supplement. ## Related pages Blood sugar basics ### [Normal blood sugar levels, and why a diabetes target is a different number](https://glucosebench.com/blood-sugar-levels) For adults without diabetes, the CDC calls a fasting blood sugar of 99 mg/dL or below normal, 100 to 125 mg/dL prediabetes, and 126 mg/dL or above diabetes; an A1C below… Read more Blood sugar basics ### [High blood sugar (hyperglycemia): the signs, and the readings that can't wait](https://glucosebench.com/high-blood-sugar) Hyperglycemia means high blood glucose; for most people with diabetes, the NIDDK says blood sugar is too high "when it is above 180 mg/dL." The usual signs are feeling… Read more Guides ### [Berberine for blood sugar: the dose, the side effects and the fine print](https://glucosebench.com/berberine-for-blood-sugar) Berberine is a compound found in plants such as barberry, goldenseal and Oregon grape. 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