Guest, we'd love to know what you think about the forum! Take the Diabetes Forum Survey 2020 »Dismiss Notice
Diabetes Forum should not be used in an emergency and does not replace your healthcare professional relationship. Posts can be seen by the public.Dismiss Notice
Guest, stay home, stay safe, save the NHS. Stay up to date with information about keeping yourself and people around you safe here and GOV.UK: Coronavirus (COVID-19). Think you have symptoms? NHS 111 service is available here.Dismiss Notice
It's normal for your blood sugar level to rise after you eat, especially if you eat a meal high in refined sugar. But if your blood sugar rises more than most people's, you might have diabetes or pre-diabetes, a condition that indicates a strong risk for developing diabetes in the future. If you already have diabetes, you doctor will recommend keeping your blood sugar within a prescribed range. A glucose tolerance test, done one to three hours after you eat a high-carbohydrate meal, can check your blood sugar levels.
When you eat carbohydrates, your body breaks down the sugars they contain into glucose. Your body can't absorb most sugars without breaking them down first. Simple sugars such as refined sugar break down very quickly; you absorb them rapidly into your bloodstream, which raises your blood sugar. In healthy people, the levels don't rise very high and they drop back to normal quickly. If you have diabetes, your levels after a meal will rise higher and stay high longer than levels in other people. This occurs because your pancreas either don't release enough insulin, the hormone that helps cells absorb glucose, or because the cells don't respond properly to insulin release.
If your doctor suspects that you have abnormal glucose levels, he might suggest doing a glucose tolerance test. You are given around 75 grams of carbohydrate after fasting for 12 hours. At one- to three-hour intervals, your doctor draws blood and analyzes your glucose levels. A normal fasting glucose is 60 to 100 milligrams per deciliter; your levels should rise no higher than 200 mg/dl one hour after eating and no more than 140 mg/dl two hours after finishing the snack. Most healthy people without diabetes have two-hour readings below 120 mg/dl.
A fasting blood sugar of between 100 and 130 mg/dl indicates impaired glucose metabolism. This means that you don't process glucose normally, which puts you at higher risk for developing diabetes. Within 10 years, most people with pre-diabetes will develop diabetes unless they change their lifestyle, according to the Joslin Diabetes Center.
If you have a blood sugar level higher than 200 mg/dl two hours after consuming the 75 grams of carbohydrate, you generally have diabetes, although other conditions such as Cushing's disease, and certain medications can also cause a rise in blood sugar levels. Once you're diagnosed with diabetes, you doctor will set a target range for your blood sugar after meals. Most doctors want you to keep your blood sugar under 180 mg/dl after eating. In some cases, your doctor will set different limits based on your specific health issues.
The higher your blood sugar rises after meals and the longer it stays high, the more likely you are to develop diabetic complications such as neuropathy, diabetic retinopathy or poor circulation. High levels of circulating glucose in your blood can damage your blood vessels.
You need to be logged in to comment