People can live with high blood sugar for years without noticing anything: symptoms often appear only after it has started to affect the nerves, kidneys and eyes. , a simple test at the right time can change the years ahead.
Who should be tested?
- Every adult from 35, then every three years if the result is normal.
- Earlier if you are overweight and have another risk factor: a parent, brother or sister with diabetes, high blood pressure or cholesterol, or an inactive lifestyle.
- Women who had diabetes in pregnancy, or who have polycystic ovaries.
- Anyone with strong thirst, frequent urination, ongoing tiredness, blurred vision or wounds that heal slowly.
Three tests, each with its own job
- Fasting blood sugar: taken after at least eight hours without food; water is fine.
- HbA1c: shows your average sugar over the last three months and needs no fasting.
- Glucose tolerance test: a reading before and two hours after a sugary drink, ordered in particular cases such as pregnancy.
How to read the numbers
These are the cut-offs international guidelines use for adults who are not pregnant; your doctor interprets your own result:
| Test | Normal | Prediabetes | Diabetes |
|---|---|---|---|
| Fasting sugar (mg/dL) | Below 100 | 100 – 125 | 126 or more |
| HbA1c | Below 5.7% | 5.7% – 6.4% | 6.5% or more |
Diabetes is not usually diagnosed on a single result: your doctor repeats the test to confirm it, unless the symptoms are clear.

Prediabetes is not a final verdict
Large studies show that losing 5 to 7% of your weight and walking briskly for 150 minutes a week more than halves the risk of prediabetes turning into diabetes. Small habits help:
- .
- Swap juices and sweet drinks for water or unsweetened tea, and cut the sugar in your tea gradually.
- Have two or three dates with your coffee rather than a whole plate.
- Sleep at least seven hours: too little sleep makes sweet cravings stronger.
When to see a doctor
See a family doctor if your result is in the prediabetes or diabetes range, or if you have symptoms even after a normal test. Very high sugar with vomiting, unusual drowsiness or fast breathing is an emergency: call an ambulance on 123.
Dr. Sarah’s Children’s Clinic’s Basic Check-up includes fasting blood sugar and HbA1c, with a doctor to go through your results at no extra cost.


