Testing for Diabetes

How is diabetes diagnosed?

The fasting blood glucose (sugar) test is the preferred way to diagnose diabetes.. After the person has fasted overnight (at least 8 hours), a single sample of blood is drawn and analysed.


For the test to give reliable results, you must be

  • In good health
  • Normally active
  • Not be taking medicines that could affect the blood glucose

The morning of the test, you should not smoke or drink tea/coffee. A few sips of water are allowed.

Normal fasting plasma glucose levels are less than 100 milligrams per deciliter (mg/dl).

Fasting plasma glucose levels of more than 126 mg/dl on two or more tests on different days indicate diabetes.

A random blood glucose test can also be used to diagnose diabetes. A blood glucose level of 200 mg/dl or higher indicates diabetes.

What is pre-diabetes?

When fasting blood glucose stays above 100mg/dl, but in the range of 100-126mg/dl, this is known as impaired fasting glucose (IFG) or pre-daibetes. While it not diagnostic of diabetes, you are at a higher risk for developing type 2 diabetes and other serious health problems, including heart disease, and stroke. Without lifestyle changes to improve their health, 15% to 30% of people with prediabetes will develop type 2 diabetes within five years.

What routine medical examinations and tests are needed for people with diabetes?

  • Monitor Blood Pressure regularly
  • Get your weight checked regularly
  • Record your home blood glucose levels and carry them when you visit your doctor
  • Get a Haemoglobin A1C test at least twice a year to determine what your average blood glucose level was for the past 2 to 3 months
  • Test your urine and blood to check your kidney function at least once a year. Include a urine mircroalbumin test
  • Test your blood lipids (fats)—total cholesterol; LDL, or low-density lipoprotein (“bad” cholesterol); HDL, or high-density lipoprotein (“good” cholesterol); and triglycerides at least once a year
  • Check your feet for sores and get a thorough foot exam at least once a year
  • Get a dental checkup twice a year
  • A dilated eye exam once a year

What is self-monitoring of blood glucose?

Monitoring your own glucose is done with a Glucose Meter. Self-monitoring is often called SMBG (self-monitoring of blood glucose). Glucose meters today are small, battery-operated devices.

When you want to test for glucose with a glucose meter you need to place a small sample of your blood on a test strip. Your skin is pricked with a lancet – like a very fast pin-prick.

These test strips are disposable. You then place the strip in the monitor. The strips are coated with glucose dehydrogenase or hexokinase that combines with glucose in blood.

The blood is usually taken from a finger. Every person with diabetes should be self-monitoring his/her blood glucose – this is especially so for people who are taking insulin.