PocDoc’s Guide to Blood Glucose Levels

Authored by: Dr Matthew Lee; BMSc, MBBS, MSc

Last reviewed: March 2025

What's in this PocDoc Article:

• Why Blood Glucose Levels Are Important
• How Can I Keep Track of My Blood Glucose Levels?
• Why is the HbA1c Test Important?
• How Often Should You Test Your HbA1c Levels?
• What Do My HbA1c Results Mean?
• Should I Be Concerned if My HbA1c Results Are Outside the Recommended Range?
• What Steps Should I Take if My HbA1c Results Are Outside the Recommended Range?
• Can I Monitor My HbA1c Levels on My Own?

What is blood glucose?

Your blood glucose levels, also known as blood sugar levels, indicate the amount of sugar currently in your blood. Everyone has some glucose in their blood, as it is used by our cells as a source of energy. However, knowing your blood glucose levels is a key part of properly managing your health, as persistently high blood glucose levels can lead to serious health complications.

Why are blood glucose levels important?

The hormone, insulin, helps to control the amount of glucose in the body. By measuring blood glucose levels, you can determine whether the insulin response is functioning properly or whether your body is using insulin properly. In individuals with type 2 diabetes, not enough insulin is being produced, or the body’s cells are not reacting to the insulin, resulting in a buildup of glucose in the bloodstream.

Persistently high blood glucose levels can harm your blood vessels, increasing the risk of conditions like coronary heart disease, kidney disease, diabetic eye disease and nerve damage.

And with around 30% of adults in the UK with undiagnosed type 2 diabetes, identifying if you have persistently high blood glucose before you are diagnosed with type 2 diabetes gives you the chance to manage blood glucose levels more effectively and lower the chances of these serious complications.

How can I keep track of my blood glucose levels?

There are several methods to measure blood glucose levels, each serving different purposes:

• Continuous glucose monitors (CGMs) – Track blood glucose fluctuations throughout the day with a sensor placed under the skin.

• Fasting glucose tests – Measure blood glucose levels after not eating for at least 8 hours.

• Oral glucose tolerance test (OGTT) – Assesses how the body processes glucose, e.g. how sensitive your insulin response is, by measuring blood glucose before and after consuming a sugary drink.

• HBA1c - the HbA1c test is considered the gold standard for monitoring diabetes because it provides a long-term picture of blood glucose levels over the past two to three months rather than just a single snapshot. Generally, individuals with higher long-term glucose levels are more likely to get diabetes.

What is HbA1c?

The HbA1c test, also known as haemoglobin A1c or glycated haemoglobin, measures the relative amount of glucose attached to the haemoglobin in red blood cells.

Haemoglobin is the protein in red blood cells responsible for carrying oxygen. Because red blood cells have a lifespan of about three months, this test gives a more comprehensive overview of blood glucose management than single glucose checks.

These results are usually shown in percentage and reflect your average blood glucose levels over the past 2–3 months.

Why is the HbA1c Test important?

HbA1c is a crucial indicator of diabetes risk and management. It is the primary diagnostic test for diabetes in the UK and helps track how well blood glucose levels have been controlled over time. A high HbA1c reading means there is consistently too much glucose in the blood, increasing the risk of serious complications such as heart disease, stroke, kidney damage, vision loss, and nerve damage.

How Often Should you test your HbA1c levels?

In general, Diabetes UK recommends that all individuals with diabetes have an HbA1c test at least once a year as part of their routine annual health checks. Regular testing helps track blood glucose control over time and allows for early intervention if needed.

However, the frequency of testing may also vary depending on individual circumstances:

• For individuals with high HbA1c or those who need more attention to their levels –It may be recommended to be done every 3 to 6 months.

For those individuals with type 2 diabetes, it is recommended that:

• Those with type 2 diabetes should have their HbA1c measured every 3 to 6 months until their levels are stable.

• Once blood glucose levels are well managed, testing frequency can be reduced to every six months to ensure continued control.

In some cases, more frequent HbA1c testing may be necessary if:

• There have been recent changes in diabetes medication or treatment plans.

• Blood glucose levels are consistently high or fluctuating.

• There are new symptoms or concerns about diabetes complications.

Your healthcare provider will determine the most appropriate testing schedule based on your individual health needs. If you are unsure about how often you should test, you may consult your doctor for personalised guidance.

What do my HbA1c results mean?

HbA1c is important in assessing your risk of developing diabetes. The following shows what various HbA1c levels may indicate:

Table showing HbA1c levels taken form Diabetes UK and NICE

• Less than 6% – Generally considered within the recommended level.

• 6 % to 6.5% – This range indicates being at high risk of developing diabetes, also commonly referred to as prediabetes.

• 6.5% or higher – This range indicates being at very high risk of developing diabetes.

Should I be concerned if my HbA1c results are higher than the recommended level?

A level higher than 6% may indicate that your blood glucose management is not optimal. The good news is that HbA1c levels, in most cases, are reversible by making lifestyle changes. A healthy HbA1c range depends on many factors. When considering why your levels may be above the recommended range, your healthcare provider will consider factors such as your past medical history, lifestyle, medications, and other relevant aspects to interpret your HbA1c results. They will then guide you as to changes you can make to ensure your blood glucose management is optimal.

If You Have Diabetes:

If you have already been diagnosed with diabetes, your HbA1c result can provide insight into how well your management plan has been working over the past few months. Consistently elevated HbA1c levels may indicate an increased risk of diabetes-related complications.

Management may involve:

• Lifestyle changes, such as diet and exercise.

• Regular blood glucose monitoring.

• Medications, such as oral tablets or insulin, if prescribed by a healthcare provider.

What steps could I take if my HbA1c results are above the recommended level?

Since many factors influence blood glucose levels and diabetes risk, there’s no single way to treat HbA1c levels higher than the recommended level. Your healthcare provider will provide guidance to you based on your own set of circumstances.

They may recommend:

• Ongoing monitoring of your HbA1c levels to track any changes over time. 

• Lifestyle adjustments, such as healthier eating, increased physical activity, and weight management, to help improve blood glucose control. 

• Medical intervention, which may include medications like metformin or insulin, if necessary, to help regulate blood glucose levels.

* If your HbA1c results are above the recommended level, it’s important to consult your healthcare provider for further evaluation and to discuss the best course of action for your individual needs.

Can I monitor my HbA1c levels on my own?

Individuals can opt to get their blood glucose levels tested by their healthcare provider; however, there are many ways for people to get accurate HbA1c levels on their own through at-home diabetes checks.

The PocDoc Diabetes Health Check will provide you with a detailed assessment of your HbA1c levels to help you stay on track with your health. It can be used by people without diabetes who want to look at their risk of getting diabetes, as well as diabetics who want to monitor their long-term blood glucose levels.

The Diabetes Health Check will also provide you with actionable steps to help you improve your blood glucose levels through diet and physical activity, as well as access to clinician support.