Is a blood sugar of 140 after eating normal?
It depends on when. Two hours after the lab's glucose drink, 140 mg/dL (7.8 mmol/L) is over the line of 140. After an ordinary meal there's no official band, and within an hour of eating, healthy people's sensors go over 140 every day.
Under 140140 to 199200 or more
What it means
The official line comes from a lab test: 2 hours after a 75 g glucose drink, under 140 mg/dL (7.8 mmol/L) is normal, 140 to 199 (7.8 to 11.0) is the prediabetes range, and 200 (11.1) or more is the diabetes range. An ordinary meal isn't that drink, so a home number after a meal is a rough check. At 1 hour, or on a sensor, there's no band: healthy people spent about 30 minutes a day above 140 in one study and about 3 hours in another.
Can this number decide it?
Only a lab test decides a band, and a diagnosis takes two results unless the number is clearly high. A finger-stick meter or a sensor can't diagnose, and a sensor runs higher than your blood.
What to do
If this was 2 hours after a meal and it happens often, get a lab A1c and fasting glucose. In the meantime, a 10-minute walk after meals and eating the carbs last both shrink the rise. See both on a plate.
When to get help now
Call 911 or go to the ER if a blood sugar stays at 300 or more, or comes with vomiting so you can't keep fluids down, fruity breath or hard breathing. Under 70 with confusion, fainting or trouble swallowing is an emergency too. Pregnancy uses tighter numbers, so take any number to your midwife or doctor, and if you take insulin or a sulfonylurea, your targets come from your prescriber.
