When blood sugar drops below 70 mg/dL, you need fast-acting carbohydrates immediately. The standard approach, called the 15-15 rule, works for most mild to moderate episodes: eat 15 grams of quick carbs, wait 15 minutes, then recheck your blood sugar. If it’s still below 70 mg/dL, repeat the process until it returns to your target range. Knowing what to eat, when to escalate to emergency treatment, and how to prevent episodes in the first place can make low blood sugar far less dangerous.
Recognizing the Symptoms
Low blood sugar produces two distinct waves of symptoms, and learning to catch the first wave is critical. The early signs come from your body’s stress response: trembling, a pounding heart, anxiety, sweating, hunger, and tingling in your lips or fingers. These are your built-in alarm system, and they typically appear when glucose dips just below 70 mg/dL.
If blood sugar continues to fall, especially below 54 mg/dL, the brain itself starts running short on fuel. That’s when confusion sets in, along with weakness, fatigue, a strange sensation of warmth, and difficulty thinking clearly. At the most severe level, you may experience seizures or lose consciousness. At that point, you can no longer treat yourself and need someone else’s help.
The American Diabetes Association classifies these stages formally. Level 1 is a reading between 54 and 69 mg/dL. Level 2 is anything below 54 mg/dL. Level 3 is defined not by a specific number but by the need for another person to help you recover, regardless of what the meter says.
What to Eat During a Low
The goal is 15 grams of carbohydrate that your body can absorb quickly. Good options include:
- Glucose tablets or glucose gel: the fastest option because they’re pure glucose with no fat or protein to slow absorption.
- 4 ounces (half a cup) of fruit juice or regular soda: not diet versions, which contain no sugar.
- 1 tablespoon of honey or sugar dissolved in water.
- A few hard candies: check the label to confirm 15 grams of carbohydrate.
Avoid reaching for chocolate, cookies, or ice cream. The fat in those foods slows digestion and delays the glucose spike you need right now. After you’ve treated the low and your blood sugar is back above 70 mg/dL, follow up with a small meal or snack that includes protein or complex carbs to keep it stable.
When Someone Can’t Swallow
If a person is unconscious, confused to the point of being unable to eat, or having a seizure, never put food or liquid in their mouth. This is a Level 3 emergency. Glucagon, a hormone that signals the liver to release stored glucose, is the appropriate treatment.
Glucagon now comes in several forms designed for non-medical people to use. A nasal powder (Baqsimi) requires no injection at all. You insert the tip into one nostril and press the plunger. The person doesn’t even need to inhale. An auto-injector (Gvoke HypoPen) works like an EpiPen: press it against the outer thigh, upper arm, or lower abdomen, and it delivers the dose automatically. Traditional glucagon kits require mixing powder with a liquid before injecting, which makes them harder to use under pressure.
After giving glucagon, call emergency services. When the person becomes alert enough to swallow, give them something to eat. If there’s no response within 15 minutes, a second dose from a new device can be given.
Preventing Lows During Exercise
Physical activity is one of the most common triggers for hypoglycemia, particularly aerobic exercise like running, cycling, or swimming. Your muscles pull glucose from the bloodstream during activity, and if insulin levels are high at the same time, blood sugar can plummet.
If you use rapid-acting insulin and plan to exercise within 90 minutes of your dose, reducing that dose can prevent a crash. The reduction depends on intensity and duration. For 30 minutes of moderate exercise, cutting the dose by about 50% is a common guideline. For 60 minutes of moderate exercise, a 75% reduction is typical. Mild exercise requires smaller adjustments, while very high-intensity bursts (like heavy weightlifting or sprints) may not require a reduction at all because they can temporarily raise blood sugar.
If exercise is unplanned, or you haven’t adjusted insulin, extra carbohydrates before and during activity are your safety net. When your blood sugar is below 90 mg/dL before starting, consuming 10 to 30 grams of fast-absorbing carbs is generally recommended. For longer sessions, roughly 0.5 to 1.0 grams of carbohydrate per kilogram of body weight per hour helps maintain levels. That’s about 35 to 70 grams per hour for a 150-pound person.
One important detail: if you use a continuous glucose monitor, be aware that readings can lag behind actual blood sugar by about 12 minutes during exercise. Your glucose may already be dropping before the sensor catches up, so checking with a fingerstick meter before and during intense activity gives you a more accurate picture.
Preventing Nighttime Lows
Nocturnal hypoglycemia is particularly risky because you’re asleep and may not notice early symptoms. Waking up with a headache, damp sheets from sweating, or feeling unusually tired can all be signs of overnight lows.
A bedtime snack can help stabilize blood sugar through the night, but the composition matters more than the size. High-protein, low-carb options work best because they digest slowly and provide a steady trickle of glucose. Good choices include a tablespoon of peanut butter with celery, a hard-boiled egg, a light cheese stick, or a serving of Greek yogurt. Avoid large carb-heavy snacks before bed, which can spike blood sugar initially and then cause a rebound drop hours later.
Reactive Hypoglycemia Without Diabetes
Not everyone who experiences low blood sugar has diabetes. Reactive hypoglycemia causes symptoms two to five hours after eating, typically after a meal high in refined carbohydrates. The body overproduces insulin in response to the sugar surge, driving blood glucose too low. Stress, illness, certain medications, and long gaps between meals can all contribute.
Dietary changes are the primary treatment. Research comparing a low-glycemic-index diet (foods that raise blood sugar slowly, like whole grains, legumes, and most vegetables) with a Mediterranean-style diet found that both approaches reduced the frequency and severity of postprandial symptoms. The key principles overlap: eat smaller, more frequent meals. Pair carbohydrates with protein and fat to slow digestion. Choose whole, minimally processed foods over refined ones. Limit sugary drinks and sweets, which create the exact spike-and-crash pattern that triggers symptoms.
Hypoglycemia Unawareness
Repeated episodes of low blood sugar can dull your body’s alarm system over time. The early warning signs (shaking, sweating, hunger) fade, and the first symptom you notice may be confusion or difficulty functioning. This is called hypoglycemia unawareness, and it’s especially common in people with long-standing type 1 diabetes.
The condition is reversible. Studies show that strictly avoiding any hypoglycemic episodes for as little as three weeks can begin restoring symptom awareness. In one study, patients who went from 21 episodes per month to zero for three weeks showed measurably improved symptom recognition. Longer avoidance periods of three to six months produced even more dramatic results, with one group dropping from roughly 20 episodes per month to about 2. The strategy involves raising blood sugar targets temporarily, checking levels more frequently (at least four to five times daily), and adjusting insulin doses aggressively to stay above the hypoglycemic threshold. It requires close work with a healthcare team, but the payoff is getting your early warning system back.
Keeping Supplies Accessible
The best treatment plan fails if you can’t reach your supplies when you need them. Keep glucose tablets or a small juice box in your bag, your car, your desk at work, and on your nightstand. If you’ve been prescribed glucagon, make sure it’s not expired and that the people around you (partner, coworkers, close friends) know where it is and how to use it. Practice with any device before an emergency, because reading instructions while panicked is far harder than it sounds.