Testing for normal blood sugar

Part 1: What is a normal blood sugar?

Introduction

The most popular search that brings in visitors to any diabetes website is: "What is a normal blood sugar?"

The answer isn't really simple, as blood sugar (glucose) can vary quite widely throughout the day, depending not only on what you eat, but also on what you are doing.

However, if you want a simple answer, here it is, using the criteria usually used by doctors.

Normal fasting blood glucose

The most meaningful instant reading of blood glucose is a fasting one. Thisl is the level you should see just before eating. To ensure that a previous meal does not skew the readings, this measurement is usually taken before breakfast.

'Normal' is reckoned to be no more than 4.6 mmol/l in Europe or 83 mg/dl in the USA, although for many healthy people fasting blood glucose around 3.9 - 4.0 mmol/l (mid to high 70 mg/dl) range is more usual.

Most doctors will tell you any fasting blood sugar under 5.6 mmol/L (100 mg/dl ) iis "normal", but there are several studies whichsuggest that a fasting blood sugar over 5 mmol/L (~ 95 mg/dl) range often predicts the beginnings of diabetes that may not be diagnosed for another several years.

Postprandial (after-meal) blood sugar

Despite what is eaten, the blood glucose level of a truly healthy person after a meal should be:

No more than 6.6 mmol/L (120 mg/dl) one or two hours after a meal. Most healthy people are under 5.5 mmol/L (100 mg/dl) two hours after eating.