1. When to Consider a Diagnosis of Diabetes


CONSIDER a diagnosis of diabetes in a patient with:

  • thirst and polyuria
  • unexplained weight loss or tiredness
  • pruritus vulvae, balanitis or recurrent 'UTI's'
  • recurrent infections
  • blurring of vision (usually an osmotic effect and not permanent)
  • discoloured or ulcerated feet
  • hypertension, ischaemic heart disease or stroke
  • obesity, with diagnosis of arterial disease or family history of diabetes.


 2. Making the Diagnosis

  • The diagnostic criteria are based internationally on WHO Guidance.
  • Diagnosis for asymptomatic patients should be done over 2 fasting visits; this is because patients may not have fasted properly for example and up to 25% are not confirmed at the 2nd visit.
  • Diagnosis for symptomatic patients can be done at one visit with fasting glucose ≥7mmol/l and HBA1c ≥48. Please Note HBA1c should not be used in children, current or recent pregnancy, suspected T1DM, HIV, known haemoglobinopathy, anaemia, pancreatic surgery/disease, rapid onset in symptoms/glucose e.g. steroid/antipsychotic medication use (or T1DM)
  • Fasting Bloods: As CTACs have taken over more blood testing, it is apparent that the logistics of 'fasting bloods' are not as easy. There is evidence (here) that 3 hours of fasting should achieve normoglycaemia in non-diabetics. This has been tested in some areas and to date not resulted in any increase in need for repeat fasting tests. As such, CTACs may wish to consider local changes in approach to accommodate this as an option to help improve access.


Process Sumary: 


Asymptomatic Patients

e.g. as part of long-term condition review taking into account risk assessment above

1. Select “Fasting Glucose” on ICE

2. If this is raised consider further testing in clinical context and if agreed:

3. Return for the “Diagnosing diabetes fasting” (as below)

Symptomatic Patients

e.g. those with current symptoms potentially attributable to diabetes

1. Select “Diagnosing diabetes fasting” on ICE. This will print labels for both grey and purple blood bottles to be collected.

2. If the glucose is >6mmol/l, HBA1c test will automatically be analysed by cascade.


Requesting on ICE




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 3. Intended Outcomes

  • Realistic, person centred approach.
  • Agree the testing frequency for diabetes screening when high risk, for example known impaired fasting glucose, history gestational diabetes, or scoring high on risk calculator (paper copy of risk calculator). Patients are supported in ownership of preventative lifestyle change.
  • Patients at moderate risk such as those with previous IHD/hypertension etc are only offered testing every 3 years, a testing frequency which is reflective of the long-term nature of the risks involved.
  • HBA1c is no longer used as a spot diagnosis tool. It is only for monitoring known diabetics, but will be cascaded automatically within the laboratory as above for those with raised fasting glucose. [Prompt will be added when selecting HBA1c “This test is for known diabetics only”].
  • There is limited use for a random glucose taken opportunistically given high risks of a raised result, and these should decrease.


Help with Requesting or Results:


4. Interpreting Results


Fasting glucose


5.5 – 6.9



None required

Consider further testing

Consider further testing















None required

See Management of Pre-diabetes

See Management of New Type 2 Diabetes


5. Patients Presenting at Diagnosis with Osmotic Symptoms


If patient has presented with osmotic symptoms (polyuria/polydipsia or weight loss) please follow specific guidance in Management of Newly Diagnosed Patients with Osmotic Symptoms.