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Symptoms and Tests for Diabetes

African American women looking over test resultsMany people have diabetes for years before it is ever diagnosed. In fact, nearly 1/3 of diabetics are have the disease but have not been diagnosed by a doctor.


Warning signs that mean a doctor’s visit is necessary include:

It is good to keep in mind that simply having one or more of these symptoms does not automatically mean that you have a diabetes diagnosis. To check your risk, the American Diabetes Association has a Diabetes Risk Test that you can take online.

Watch below to get a clearer picture of the symptoms of diabetes!

Tests to Diagnose Diabetes

If your doctor suspects the possibility that you have diabetes, he or she may have you take some of the following tests.

Fasting Blood Glucose Test

Because eating food raises your blood sugar – also called “glucose” – level, you will need to fast before you take this test.  Fasting means that you do not eat for a period of time, usually 12 hours before the test.  After you have fasted for 12 hours, the amount of glucose in your blood will be measured to decide if you have diabetes. The glucose level in a healthy person stays below 126 milligrams/deciliter (mg/dL).  If your level is higher than this, your sugar level is elevated, and you will likely need to take more tests to determine if you have diabetes. Even values above 100 mg/dL are higher than normal and could be a sign of a pre-diabetes state called Impaired Glucose Tolerance.  This means you are at increased risk for getting diabetes. Doctors prefer to use the fasting blood glucose test because it is very easy to perform.

Glucose Tolerance Test (Oral Glucose Test)

After fasting from food and drink for at least eight hours, you will be given a drink containing a measured amount of glucose. Several blood samples are drawn for two hours afterward, and the levels of blood glucose are measured and recorded.

  • A reading over 200 mg/dL blood glucose means diabetes.
  • A reading between 150 and 200 mg/dL is a grey area.  At this level, you may be “pre-diabetic,” which means you may be at risk for getting diabetes.
  • Blood glucose levels in a diabetic will rise faster and stay higher longer than in a healthy person.

This test is the most accurate way to diagnose diabetes.


Random Blood Glucose Test

Blood glucose levels can be tested at any time with a finger prick and a glucose monitor. Because food and drink can cause your glucose levels to change drastically, a health professional usually does this test after a meal. If the levels look suspiciously high, your doctor will likely order a fasting blood glucose test.


Tests to Monitor Blood Glucose Levels for Diabetics

If you are a diabetic, the following tests can help you manage your diabetes.

Self-Monitoring of Blood Glucose (SMBG)

Glucose levels can rise and fall quite dramatically, so you need to measure your glucose levels several times a day to keep a close watch on the levels.

  • If there is too much sugar in your blood, you either
  • ate too many sugars or “carbohydrates”
  • or did not take enough insulin.
  • If your blood sugar levels are too low, the opposite is true. Either you:

    • did not eat enough sugars or “carbohydrates”
    • Or took too much insulin or oral medicine.

However, many diabetics are able to manage their blood sugar levels without taking insulin.  They do this by carefully controlling their diet and exercise habits.

Hemoglobin A1 C Test

The hemoglobin A1 C Test monitors how well a diabetic is controlling his or her blood sugar over longer periods of time. 

It can give accurate readings without being affected by current glucose levels.

Glucose tends to attach itself to a protein in the blood called hemoglobin.  (Hemoglobin is the iron-containing protein that carries oxygen and colors the blood red.) Glucose combined with hemoglobin results in a new compound called “glycohemoglobin”.

The A1 C test measures the percentage of hemoglobin in the body that is made of up this new compound, glycohemoglobin.

  • Healthy people usually have less than 7% of the hemoglobin in their body made up of glycohemoglobin.  (This means that less than 7% of the hemoglobin in the body has glucose attached to it.)
  • Readings above this 7% marker mean that sugar levels are not being controlled very well over the last several months.

Doing this test regularly over a period of time shows how well a diabetic is controlling overall glucose levels, instead of how it is being controlled at that moment.


More features about Diabetes:






For more information:

Go to the Diabetes health topic.