Diagnosing Diabetes - Wheaton Franciscan Healthcare

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Diagnostics

Understanding Diabetes & How It's Diagnosed

High blood levels of glucose can cause several problems, including:

  • Blurry vision
  • Excessive thirst
  • Fatigue
  • Frequent urination
  • Hunger
  • Weight loss

However, because type 2 diabetes develops slowly, some people with high blood sugar experience no symptoms at all.

Type 1 Symptoms

Patients with type 1 diabetes usually develop symptoms over a short period of time. The condition is often diagnosed in an emergency setting.

  • Fatigue
  • Increased thirst
  • Increased urination
  • Nausea
  • Vomiting
  • Weight loss in spite of increased appetite

Type 2 Symptoms

  • Blurred vision
  • Fatigue
  • Increased appetite
  • Increased thirst
  • Increased urination

Exams & Tests

A urine analysis may be used to look for glucose and ketones from the breakdown of fat. However, a urine test alone does not diagnose diabetes.

The following blood tests are used to diagnose diabetes:

Fasting Blood Glucose Level

Diabetes is diagnosed if higher than 126 mg/dL on two occasions. Levels between 100 and 126 mg/dL are referred to as impaired fasting glucose or prediabetes. These levels are considered to be risk factors for type 2 diabetes and its complications.

Hemoglobin A1c Test

This test has been used in the past to help patients monitor how well they are controlling their blood glucose levels. In 2010, the American Diabetes Association recommended that the test be used as another option for diagnosing diabetes and identifying pre-diabetes. Levels indicate:

  • Normal: Less than 5.7%
  • Pre-diabetes: Between 5.7% - 6.4%
  • Diabetes: 6.5% or higher

Oral Glucose Tolerance Test

Diabetes is diagnosed if glucose level is higher than 200 mg/dL after 2 hours. (This test is used more for type 2 diabetes.)

Random (Non-Fasting) Blood Glucose Level

Diabetes is suspected if higher than 200 mg/dL and accompanied by the classic diabetes symptoms of increased thirst, urination, and fatigue. (This test must be confirmed with a fasting blood glucose test.) 

Persons with diabetes need to have their hemoglobin A1c (HbA1c) level checked every three to six months. The HbA1c is a measure of average blood glucose during the previous two to three months. It is a helpful way to determine how well treatment is working.

It’s also important to have your cholesterol and triglyceride levels checked each year (aim for LDL levels below 100 mg/dL).

We’re Here to Help

To help answer your questions or to schedule an appointment with a diabetes specialist, please call 262-687-6345. 

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