When your blood glucose drops below 70 mg/dL, you need fast-acting sugar immediately. A reading below 54 mg/dL is considered severely low and can become a medical emergency. Acting quickly matters because your brain depends on a steady supply of glucose, and delays of even a few minutes can lead to confusion, loss of consciousness, or seizures.
How to Recognize a Low
The early warning signs of low blood sugar tend to come on fast. You may notice shakiness, sweating, a pounding or irregular heartbeat, sudden hunger, or a feeling of anxiety that seems to come from nowhere. Dizziness, headache, and tingling in your lips or tongue are also common. Some people look noticeably pale.
As blood sugar continues to fall, the symptoms shift from physical to cognitive. Confusion sets in, you may have trouble completing simple tasks, your speech can become slurred, and your vision may blur. If levels drop further into severe territory, seizures and loss of consciousness become possible. Recognizing the earlier signs and treating them right away is the simplest way to prevent things from escalating.
The 15-15 Rule
The standard approach to treating a mild or moderate low is called the 15-15 rule: eat or drink 15 grams of fast-acting carbohydrates, wait 15 minutes, then recheck your blood sugar. If it’s still below 70 mg/dL, repeat the process. Keep going until your reading is back in your target range.
The key word here is “fast-acting.” You want sugar that hits your bloodstream quickly, not something with fat or fiber that slows digestion. Good options for 15 grams of quick carbs include:
- Glucose tablets: these are the most precise option since each tablet lists its exact carb count
- Half a cup of fruit juice (apple or orange work well)
- One cup of a sports drink
- One tablespoon of honey, sugar, or jelly
Avoid chocolate bars, cookies, or ice cream as your first-line treatment. The fat in these foods slows sugar absorption, which is the opposite of what you need in the moment. Save the real food for the next step.
What to Eat After Your Levels Stabilize
Once your blood sugar is back above 70 mg/dL, eat a balanced snack or small meal that includes both protein and carbohydrates. Think peanut butter on whole-grain toast, cheese and crackers, or a handful of nuts with a piece of fruit. The protein and complex carbs help sustain your blood sugar and prevent another drop in the following hours. Skipping this step is a common mistake that leads to a second low shortly after the first one resolves.
When Someone Can’t Treat Themselves
Severe hypoglycemia, where a person is unconscious, seizing, or too confused to swallow safely, requires glucagon. This is a hormone that signals the liver to release stored glucose into the bloodstream. If you live with or care for someone at risk of severe lows, keep a glucagon kit accessible and know how to use it before an emergency happens.
Three forms of glucagon are available. A nasal spray delivers powdered glucagon through the nose in one step, with no needles involved, making it the easiest for a bystander to administer. A pre-mixed pen works like an EpiPen: remove the cap, inject into the outer thigh, upper arm, or lower abdomen at a 90-degree angle. The third option is a traditional kit that requires mixing a powder with a liquid before injecting, which is more complicated under pressure. All three can be given to someone who is unconscious.
After giving glucagon, roll the person onto their side. Vomiting is a common side effect, and lying face-up creates a choking risk. Call emergency services if the person doesn’t regain consciousness within 15 minutes.
Lows That Happen During Sleep
Nocturnal hypoglycemia is particularly tricky because you can’t feel the usual warning signs while you’re asleep. A bed partner might notice restless or irritable sleep, clammy skin, trembling, sudden changes in breathing patterns, or a racing heartbeat. Nightmares are another hallmark, sometimes intense enough to jolt you awake.
If you suspect overnight lows, a continuous glucose monitor with a low-alarm feature can wake you when levels start to drop. Setting an alarm for the early morning hours (around 2 or 3 a.m.) to check your blood sugar manually for a week or two can help you identify how often it’s happening. In many cases, the solution involves adjusting the timing or dose of evening medications, which is something to work through with your care team.
When You Stop Feeling the Warning Signs
Some people who experience frequent lows gradually lose the ability to sense them. This is called hypoglycemia unawareness, and it’s more common in people who have had diabetes for many years or who have repeated episodes of low blood sugar. The body essentially recalibrates, muting the sweating, shaking, and racing heart that normally serve as alarms.
The good news is that awareness can often be restored. The primary strategy is carefully avoiding any hypoglycemic episodes for several weeks. This may mean temporarily running blood sugar targets a bit higher to give the body time to reset its alarm system. Over time, the early warning signs typically return. A continuous glucose monitor is especially valuable during this period because it provides an external safety net while your internal one recovers.
Practical Steps to Prevent Repeat Episodes
A single low is usually easy to handle. Repeated lows suggest something in your routine needs adjusting. Keep a log of when your lows happen, what you ate beforehand, and how active you were that day. Patterns tend to emerge quickly: maybe your blood sugar drops every time you exercise in the afternoon, or consistently dips before lunch.
Carry fast-acting sugar with you at all times. Glucose tablets in a jacket pocket, a juice box in your bag, or a small tube of cake gel in your glove compartment all work. The worst time to realize you don’t have anything is when your hands are already shaking. If you drive, check your blood sugar before getting behind the wheel and pull over immediately if you feel symptoms coming on.
For young children, the 15-gram dose may be too much. Infants and toddlers generally need a smaller amount of carbohydrate to correct a low, so parents should have a specific number from their child’s doctor rather than guessing.