Is Your Blood Sugar
Normal, High or Low?

A normal fasting blood sugar is between 70 and 99 mg/dL (3.9–5.5 mmol/L). Two hours after a meal, below 140 mg/dL (7.8 mmol/L) is considered normal. These ranges are set by the World Health Organization and the American Diabetes Association.

A fasting blood sugar of 126 mg/dL (7.0 mmol/L) or higher on two separate occasions indicates diabetes. A random glucose of 200 mg/dL (11.1 mmol/L) or higher with symptoms may also confirm diabetes. Always get a confirmed diagnosis from your doctor.

Pre-diabetes is when fasting blood sugar is between 100–125 mg/dL (5.6–6.9 mmol/L). It means your blood sugar is higher than normal but not yet in the diabetic range. With lifestyle changes — better diet, more exercise, weight loss — many people reverse pre-diabetes before it progresses.

Hypoglycemia is when blood sugar drops below 70 mg/dL (3.9 mmol/L). It is most common in people taking insulin or certain diabetes medications. Causes include skipping a meal, exercising without eating, or taking too much insulin. Symptoms include shakiness, sweating, confusion and dizziness. Treat immediately with fast-acting carbs like juice or glucose tablets.

Fasting blood sugar is measured after at least 8 hours without eating or drinking anything except water. Post-meal (postprandial) blood sugar is measured 1–2 hours after eating. Both are important: fasting checks baseline glucose control, while post-meal checks how well your body handles carbohydrates.

No. A single blood sugar reading is not enough to diagnose diabetes. Diagnosis requires at least two separate fasting blood tests above 126 mg/dL, or an HbA1c of 6.5% or higher, confirmed by your doctor. This tool is a guide to help you understand your reading — not a diagnostic device.