How to Spot Low Blood Sugar Warning Signs

Low blood sugar, called hypoglycemia by doctors, happens when the sugar in your blood drops below about 70 mg/dL. For people who take insulin or certain diabetes pills, this can come on in minutes and needs to be treated right away. The good news is that your body sends clear warning signals, and once you know what to watch for, you can fix it at home with a few sips of juice or a handful of glucose tablets.

The earliest signs are usually shaky hands, a fast heartbeat, and a sudden feeling of hunger. You may sweat even though the room is not warm, or feel a wave of dizziness when you stand up. Many people describe a strange jittery feeling, like they drank too much coffee. These symptoms come from adrenaline, which your body releases to push sugar out of storage.

If the low keeps dropping, the brain starts running short on fuel. That is when thinking gets fuzzy, words come out wrong, and simple tasks feel impossible. Some people get cranky or weepy without knowing why. A spouse or grown child often notices the change before you do, which is one reason to tell people close to you what to look for.

Very low blood sugar — below 54 mg/dL — is a medical emergency. The person may pass out, have a seizure, or be unable to swallow. In that case, do not try to give them food or drink. Instead, give a glucagon shot or nasal spray if you have one, then call 911.

Nighttime lows are sneaky because you sleep through them. Signs the next morning include damp pajamas, a pounding headache, or waking up confused. If this happens more than once, call your doctor — the bedtime medication dose may need to come down.

The standard treatment is the 15-15 rule: have 15 grams of fast sugar, wait 15 minutes, then test again. Repeat until the meter reads above 70 mg/dL.