Glucose (Blood)
Glucose serves as the main source of energy for the body and its levels are tightly regulated by a variety of hormones, of which insulin is perhaps the most well known. The absence of insulin (type 1 diabetes mellitus (DM)) or insensitivity/resistance to its activity (type 2 DM) are characterised by hyperglycaemic states that initiate micro- and macro-vascular disease. Hypoglycaemia is a common presentation of (neonatal) inborn error of metabolism, insulinoma, factitious or over-administration of exogenous insulin, states of cachexia and hypopituitarism.
Diagnosis of DM, impaired glucose tolerance or insulin resistance
Monitoring of established DM
Diagnosis of metabolic disorders, endocrine neoplasia and hypopituitarism
| Over 4 weeks old, fasting | 3-6 mmol/L |
| Over 4 weeks old, random | 3.0-7.8 mmol/L |
| Less than 4 weeks old | 2.2-7.8 mmol/L |
2x random glucose >11.1 mmol/L: diagnostic of DM.
2x fasting glucose >7.0 mmol/L: diagnostic of DM.
Oral glucose tolerance test (OGTT) 2h postprandial >11.1 mmol/L: diagnostic of DM.
Fasting glucose <7.0 mmol/L AND 2h postprandial OGTT 7.8-11.1 mmol/L: impaired glucose tolerance.
Fasting glucose 6.1-6.9 mmol/L (AND if available 2h OGTT <7.8 mmol/L): impaired fasting glycaemia
Fasting glucose 5.5-6.9 mmol/L: consider referral into the NHS Diabetes prevention programme.
Record last updated
August 20, 2025
Sample Container
2ml Fluoride oxalate Vacutainers (Grey top)
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Test Results
Yes, we have a Pathology User Guide
Yes. Please email your request to Imperial.nwlpcustomerservice@nhs.net
Results are communicated to clinical staff and are normally not communicated direct to patients either on telephone requests or in written report. If you need to contact us please click here to view the contact details page
Please contact the Customer Service Team Monday to Friday from 8:30am – 6:00pm on 0203 313 5353. Alternatively, see the Pathology User Guide for how to contact the relevant department. If advice is not urgent you can also email your query to Imperial.nwlpcustomerservice@nhs.net
Additional tests may be added by discussion with the relevant laboratory. The time limit for adding additional tests to a sample already received in the laboratory will depend on the type of sample and the department it was sent to.
Information on the repertoire of tests performed by pathology, including reference ranges, turnaround times and specimen requirements, can be found in the test directory.
Phlebotomy services are not managed by NWLP. For further information please see:
Imperial College Healthcare Trust Phlebotomy services
Chelsea and Westminster Hospital NHS Foundation Trust Phlebotomy services
NWLP operates UKAS accredited medical laboratories as per the references below. The current scope of accreditation for all NWLP’s laboratories can be found on the UKAS website.
UKAS accredited medical laboratory/medical diagnostic service:
- Clinical Biochemistry No. 8673
- Haematology and Blood Transfusion No. 8674
- Infection & Immunity Sciences (Including Immunology, Virology, Microbiology and Histocompatibility and Immunogenetics ) No. 8659
- Cellular Pathology (Including Histopathology, Cytology and Molecular Pathology) No. 9615
If you require copies of our certificate of accreditation and associated documentation please contact Imperial.nwlpcustomerservice@nhs.net.
UKAS requires the laboratories to be accredited for a particular repertoire/scope (ISO15189), any changes or additions to repertoire require assessment by UKAS (extension to scope).
The BD Hospital Tube Guide, BD GP Tube Guide and BD Paediatric Tube Guide provide visual references to the correct tube types and collection instructions.
Home testing
INSTRUCTION SHEET FOR BLOOD SAMPLE COLLECTION
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Our accreditations
Upholding excellence in diagnostic standards
Our laboratories are accredited by the UK Accreditation Service (UKAS) against the international standard ISO15189:2022. UKAS is the accreditation body for the UK that assesses medical laboratories.
Find out more about our accreditations on the UKAS website.
UKAS website