fasting 140 and postprandial is 240

(Chennai. Tamil Nadu, India)

Original Question

I am a 53-year-old man. My fasting blood sugar is 140 mg/dL and my postprandial blood sugar is 240 mg/dL. Is this very dangerous?

Quick Answer:

A fasting glucose of 140 mg/dL (7.8 mmol/L) and a post-meal glucose of 240 mg/dL (13.3 mmol/L) are both high. If you have not already been diagnosed with diabetes, a fasting laboratory result of 140 mg/dL is in the diabetes range and should be confirmed with proper testing.

What Does a Fasting Sugar of 140 Mean?

For diagnosis, a laboratory fasting plasma glucose of 126 mg/dL or higher is in the diabetes range. In someone without clear symptoms or a hyperglycemic crisis, an abnormal diagnostic result usually needs confirmation with repeat testing or another diagnostic test.

Therefore, a fasting result of 140 mg/dL should not be dismissed as only slightly elevated. See our
fasting blood sugar guide.

What Does a Postprandial Sugar of 240 Mean?

A post-meal glucose of 240 mg/dL is high. For many nonpregnant adults who already have diabetes, a commonly used treatment goal is a peak post-meal glucose below 180 mg/dL, measured about 1–2 hours after the beginning of a meal.

However, a home glucose reading after an ordinary meal is not the same as a formal oral glucose tolerance test and should not be used by itself to diagnose diabetes.

See our guide to
blood sugar levels after eating.

What Should You Do Next?

Arrange a medical appointment soon.

Ask for

a fasting plasma glucose measured in a laboratory.

Ask for an HbA1c test.

Your doctor may repeat testing or order another diagnostic test if needed.

If you already have diabetes, review your glucose log and current treatment with your clinician.

Do not increase, stop or change diabetes medication on your own. If these readings occurred while you are already taking treatment, your clinician may need to review the dose, timing, diet, activity and overall treatment plan.

What Can Help Lower Glucose?

Limit sugary drinks and large portions of refined carbohydrates.

Choose vegetables, legumes, whole grains and appropriate portions of carbohydrate.

Include protein with meals.

Exercise regularly if your doctor says it is safe.

Keep a record of fasting and post-meal readings.

You can compare your readings with our
acceptable blood glucose targets.

Is This an Emergency?

A glucose of 240 mg/dL without severe symptoms is not always an emergency by itself. Seek urgent medical care if high glucose occurs with vomiting, confusion, difficulty breathing, severe dehydration, abdominal pain, inability to keep fluids down or unusual drowsiness.

Also contact your doctor promptly if you have excessive thirst, frequent urination, blurred vision or unexplained weight loss.