If your blood sugar drops to 70 mg/dL or below, eat or drink 15 grams of fast-acting carbohydrates immediately, then wait 15 minutes and recheck. This approach, called the 15-15 rule, is the standard first response and works for most mild to moderate episodes. If your blood sugar is still under 70 mg/dL after 15 minutes, repeat the process until it returns to your target range.
Recognizing the Symptoms
Low blood sugar often announces itself with a cluster of symptoms that come on quickly: a fast heartbeat, shaking, sweating, sudden hunger, and a wave of anxiety or nervousness. These are your body’s early alarm signals, driven by a rush of stress hormones trying to push glucose back into your bloodstream. At this stage you can still treat yourself effectively.
If blood sugar keeps falling, the symptoms shift. You may feel weak, have trouble walking or seeing clearly, act confused, or struggle to think straight. Below 54 mg/dL is considered clinically significant hypoglycemia. At the most severe level, seizures and loss of consciousness can occur, and you’ll need someone else to help you. The faster you act on those early warning signs, the less likely you are to reach that point.
What to Eat or Drink Right Away
You need something that raises blood sugar fast, not a meal or a snack with fat and protein that will slow digestion. Each of the following delivers roughly 15 grams of fast-acting carbohydrates:
- Glucose or dextrose tablets: 4 to 5 tablets (the preferred option because the dose is precise)
- Fruit juice or regular soda: two-thirds of a cup (about 150 mL), not diet versions
- Honey: 1 tablespoon
After eating or drinking one of these, wait a full 15 minutes before rechecking. It’s tempting to keep eating because you still feel shaky, but overcorrecting can send your blood sugar too high. If the recheck still shows a level under 70 mg/dL, have another 15 grams and wait again. Once your number is back in range, eat a small meal or snack with some protein and complex carbohydrates to keep it stable. Young children, especially infants and toddlers, typically need less than 15 grams per round.
What to Do in a Severe Episode
Severe hypoglycemia means you’re too confused, weak, or unconscious to treat yourself. This is an emergency that requires help from someone nearby.
If you live with diabetes and take insulin, talk to your doctor about having glucagon on hand. Glucagon is a hormone that signals your liver to release stored glucose. It comes in several forms that a family member, roommate, or coworker can use without medical training: a nasal spray (a single puff into one nostril), a pre-filled auto-injector that goes into the thigh (similar to an epinephrine pen), and an older emergency kit with a powder that gets mixed with sterile water before injection.
If you’re helping someone who has lost consciousness or can’t swallow, never try to put food or liquid in their mouth. Use their glucagon if you know how. Call 911 immediately if no glucagon is available, if you’re unsure how to administer it, or if the person doesn’t regain consciousness after receiving it.
Why Some People Stop Feeling Symptoms
A condition called hypoglycemia unawareness can develop when someone experiences repeated low blood sugar episodes over time. Each episode lowers the threshold at which the body sounds its alarms. Eventually, the usual warning signs (shaking, sweating, fast heartbeat) stop appearing, and blood sugar can drop dangerously low without any obvious signal. This is more common in people who have had diabetes for 20 or 30 years, those who aim for very tight glucose control, and people managing cognitive conditions like dementia or depression that make diabetes harder to track.
If you’ve noticed that you no longer feel lows the way you used to, a continuous glucose monitor can be a critical safety tool. It tracks your glucose around the clock and alerts you when levels start dropping, catching what your body no longer catches. Knowing your blood sugar before you drive, exercise, or go to sleep becomes especially important. There is some good news: research shows that if you can avoid hypoglycemic episodes for a sustained period, your body can “reset” and begin producing warning symptoms again.
Preventing the Next Episode
Treating a low is the immediate priority, but understanding what caused it helps you avoid the next one. The most common triggers are taking too much insulin or certain diabetes medications (particularly sulfonylureas), skipping or delaying meals, exercising harder or longer than usual without adjusting food or medication, and drinking alcohol on an empty stomach.
A few practical habits reduce your risk significantly. Keep fast-acting carbohydrates in your bag, car, desk, and nightstand so you’re never caught without them. Check your blood sugar before driving. If you’re starting a new exercise routine, monitor your levels more frequently until you understand how your body responds. And if you’re having repeated lows, bring a log of those episodes to your next appointment so your medication or dosing schedule can be adjusted.