Know your Diabetes ❯ How to diagnose

How to diagnose

Diabetes has classic symptoms, but many may not display any symptoms till it’s too late.
Symptoms and signs of Diabetes
  • Weight change (gain or loss) with polyphagia (increased hunger)
  • Increased thirst (polydipsia)
  • Frequent urination (polyuria)
  • Extreme fatigue or lack of energy
  • Blurred vision
  • Frequent or recurring infections (Especially urine, genital and skin infections)
  • Cuts and bruises, those are slow to heal
  • Tingling sensation or numbness in the hands or feet
  • Trouble of getting or maintaining an erection

But it is important to remember that many people with type 2 Diabetes may display no symptoms.

Diagnostic Tests 
Your doctor will order one or more following tests to diagnose your Diabetes
Fasting Blood Sugar (FBS)
For this test, you need to refrain from eating and drinking except for water for eight hours. A test result of 126mg/dL or more will indicate Diabetes.   
Random Blood Sugar (RBS)
This test can be performed at any time of the day, regardless of the time of your last meal or drink. A test result of 200mg/dL or more with symptoms of Diabetes indicates Diabetes.
This test can be done at any time of the day, regardless of the time of your last meal or drink. A test result of 6.5% or more indicates Diabetes.  
Oral Glucose Tolerance Test (OGTT)
For this test, you will be given a glucose drink containing 75g of glucose, provided that you have fasted for 8 hours prior to test. Two hours later the drink, your blood sugar will be measured.
FBS(mg/dL) RBS /2hr BS(mg/dL) HbA1C(%)
Normal <100 <140 <5.6
Diabetes Mellitus >126 >200 >6.5
PreDiabetes 100 - 125 140 - 199 5.7 – 6.5


Sri Lanka Diabetes Federation is a comprehensive national programme, which has been designed with the key objective of preventing diabetes and related complications. It was launched on 01.10.2015 as the public arm of Sri Lanka College of Endocrinologists.
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Sri Lanka Diabetes Federation
C/O Sri lanka college of Endocrinologists
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