How does diabetes screening work?

An HbA1c test reflects average blood glucose over the preceding period and usually does not require fasting. A fasting glucose test measures glucose after a period without food. In some situations, an oral glucose test compares blood samples before and after a glucose drink. Your clinician chooses the test according to your symptoms, medical history and the reason for testing.

A result can suggest normal glucose, Prediabetes or diabetes, but one result may need confirmation. Recent illness, pregnancy, anaemia and some medicines can affect interpretation. Screening can find Type 2 Diabetes before a person notices changes, while symptoms such as excessive thirst or frequent urination should be assessed rather than waiting for routine screening.

Ask whether fasting is required and follow the laboratory instructions. Tell the clinician about medicines, pregnancy, recent illness and any symptoms. Drink water unless you have been given different instructions, and bring previous results if available. If the result is raised, the next step may be repeat testing, a fuller assessment, or a discussion about food, activity and Diabetes Medication Management.

Screening is one part of prevention. A Diabetes Education Programme can help you understand readings, meal patterns and practical changes. A Continuous Glucose Monitor is different from a screening blood test and is not suitable for every person.

Arrange prompt medical assessment for marked thirst, frequent urination, vomiting, dehydration, unusual drowsiness, confusion or rapid breathing. Seek emergency help if someone is difficult to wake or breathing is severely affected. Do not wait for a routine screening appointment when symptoms are sudden or severe.

Ask which test you are having, whether fasting is needed, what the result means, and whether it needs confirmation. You may also ask when to repeat testing, how risk factors affect follow-up, and what support is available if the result indicates Prediabetes or diabetes.