An HbA1c of 114 mmol/mol is a seriously elevated result, and understanding the average blood sugar calculated from this HbA1c is an important first step towards taking action. Using validated ADAG/NGSP conversions, this result corresponds to approximately 12.6% in NGSP units and an estimated average glucose (eAG) of around 17.4 mmol/L — more than double the NHS diagnostic threshold for diabetes. This article explains what that figure means clinically, how the conversion is calculated, what UK guidelines say, the associated health risks, and the steps you and your healthcare team can take to bring your blood sugar under control.

What an HbA1c of 114 mmol/mol Means for Your Blood Sugar

An HbA1c of 114 mmol/mol equates to an estimated average glucose of ~17.4 mmol/L, reflecting sustained, severely elevated blood glucose over the preceding two to three months and indicating very poor diabetes control.

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An HbA1c of 114 mmol/mol is a significantly elevated result that indicates very poor long-term blood glucose control. HbA1c — or glycated haemoglobin — is a blood test that reflects your average blood sugar levels over the preceding two to three months. It works by measuring the proportion of haemoglobin (the protein in red blood cells) that has glucose attached to it. The higher your blood glucose has been over that period, the higher your HbA1c result will be.

Using validated ADAG/NGSP conversions, an HbA1c of 114 mmol/mol corresponds to approximately 12.6% in NGSP (percentage) units and an estimated average glucose (eAG) of approximately 17.4 mmol/L. For context, NICE and NHS guidance for people with diabetes generally sets individualised HbA1c targets at 48 or 53 mmol/mol depending on treatment regimen and individual factors such as hypoglycaemia risk (see NICE NG28 and NG17). A result of 114 mmol/mol is more than double the diagnostic threshold for diabetes (48 mmol/mol on two separate occasions in the absence of symptoms, or once if symptoms are present), placing it firmly in the category of severely uncontrolled diabetes.

It is important to understand that this is not a single snapshot of your blood sugar at one moment in time, but rather a sustained average. This means that blood glucose levels have likely been consistently and substantially elevated over a prolonged period. Receiving a result this high can feel alarming, but it is a clinically important finding that enables your healthcare team to take prompt, targeted action to reduce your risk of serious complications.

How Average Blood Glucose Is Calculated from HbA1c Results

Using the validated ADAG two-step formula, HbA1c 114 mmol/mol converts to ~12.6% (NGSP), then to an eAG of ~17.4 mmol/L; this estimate should not replace capillary or CGM readings for day-to-day decisions.

The relationship between HbA1c and estimated average glucose (eAG) is well established and is used clinically to help patients and clinicians understand what an HbA1c figure means in practical, everyday terms. The conversion is based on data from the ADAG (A1c-Derived Average Glucose) study (Nathan et al.), which correlated HbA1c values with continuous glucose monitoring readings across a large international population.

The validated two-step conversion for HbA1c expressed in IFCC units (mmol/mol) is:

Step 1 — Convert to NGSP percentage: HbA1c (%) = (0.09148 × HbA1c in mmol/mol) + 2.152

Step 2 — Derive eAG: eAG (mmol/L) = (1.59 × HbA1c in %) − 2.59

Applying this to an HbA1c of 114 mmol/mol:

• Step 1: (0.09148 × 114) + 2.152 = 10.43 + 2.152 = ≈ 12.6%

• Step 2: (1.59 × 12.6) − 2.59 = 20.03 − 2.59 = ≈ 17.4 mmol/L

This figure is an estimate and should not be used in place of capillary blood glucose readings or continuous glucose monitoring (CGM) for day-to-day treatment decisions. Diabetes UK provides a validated unit converter to help patients interpret their HbA1c results.

It is also important to note that HbA1c is not a reliable measure in certain situations. Conditions and circumstances that can falsely raise or lower the result include: haemolytic anaemia, haemoglobin variants (haemoglobinopathies), iron deficiency anaemia, chronic kidney disease, recent blood transfusion, and certain medications. HbA1c should also not be used for diagnosis in pregnancy, children and young people, or in adults presenting with acute symptoms of hyperglycaemia (where type 1 diabetes or another acute cause must be excluded promptly). If any of these factors apply, your GP or diabetes team may use alternative measures such as fructosamine testing or more frequent self-monitored blood glucose readings. Always discuss your result in the context of your full medical history with a qualified clinician.

What the NHS and NICE Say About HbA1c Levels This High

NICE NG28 and NG17 classify an HbA1c of 114 mmol/mol as severely uncontrolled diabetes, recommending urgent clinical review, treatment intensification, and consideration of specialist referral and structured education.

According to NICE guidelines (NG28 for type 2 diabetes and NG17 for type 1 diabetes in adults) and NHS clinical standards, an HbA1c of 114 mmol/mol represents severely uncontrolled diabetes and warrants urgent clinical review and intensification of treatment.

NICE defines the diagnostic threshold for type 2 diabetes at 48 mmol/mol (with appropriate caveats — see above). For adults with type 2 diabetes, NICE NG28 recommends individualised HbA1c targets, typically 48 mmol/mol for those managed by lifestyle or certain medications with low hypoglycaemia risk, or 53 mmol/mol where hypoglycaemia is a concern or where tighter control is not appropriate. For adults with type 1 diabetes, NICE NG17 recommends a target of 48 mmol/mol or below, again agreed individually between the patient and their clinical team, taking into account hypoglycaemia risk and quality of life. Regardless of diabetes type, an HbA1c of 114 mmol/mol is a significant clinical concern requiring prompt intervention — in many cases, same-week specialist review and insulin initiation or intensification will be appropriate.

The NHS also highlights that HbA1c results at this level are associated with a substantially increased risk of both microvascular complications (such as retinopathy, nephropathy, and neuropathy) and macrovascular complications (such as cardiovascular disease and stroke). NICE recommends that clinicians review medication, lifestyle factors, and potential barriers to self-management when HbA1c remains persistently elevated. Referral to a specialist diabetes team, structured education programmes such as DESMOND (for type 2 diabetes) or DAFNE (for type 1 diabetes), and consideration of additional pharmacological therapies may all be appropriate at this level. The specific medicines considered will depend on diabetes type and individual circumstances (see the section on lowering your HbA1c below).

Health Risks Associated with Severely Elevated HbA1c

An HbA1c of 114 mmol/mol substantially raises the risk of microvascular complications (retinopathy, nephropathy, neuropathy) and macrovascular events (heart attack, stroke), as well as acute emergencies such as DKA and HHS.

Sustained blood glucose levels reflected by an HbA1c of 114 mmol/mol carry a significant burden of health risk. Chronically elevated glucose causes damage to blood vessels and nerves throughout the body, and the higher and more prolonged the elevation, the greater the cumulative harm. Understanding these risks is not intended to cause alarm, but to underscore the importance of timely intervention.

Microvascular complications — those affecting small blood vessels — include:

• Diabetic retinopathy: damage to the blood vessels of the retina, which can lead to vision loss if untreated

• Diabetic nephropathy: progressive kidney damage that can eventually lead to chronic kidney disease or kidney failure

• Diabetic peripheral neuropathy: nerve damage causing pain, tingling, numbness, or weakness, most commonly in the feet and legs

Macrovascular complications — affecting larger blood vessels — include an increased risk of:

• Coronary heart disease and heart attack

• Stroke and transient ischaemic attack (TIA)

• Peripheral arterial disease, which can impair circulation to the limbs

At very high glucose levels, there is also a risk of acute metabolic emergencies. Diabetic ketoacidosis (DKA), more common in type 1 diabetes, and hyperosmolar hyperglycaemic state (HHS), more common in type 2 diabetes, are both potentially life-threatening conditions that can develop when blood glucose is severely elevated. NHS and JBDS (Joint British Diabetes Societies) guidance provides detailed advice on recognising and responding to these emergencies.

Additionally, poorly controlled diabetes impairs immune function, increasing susceptibility to infections and slowing wound healing. Foot complications in particular require vigilant monitoring, as reduced sensation and poor circulation can allow injuries to progress unnoticed. If you have any active foot problems — including ulcers, infection, or a suspected acute Charcot foot — you should be referred promptly to your local NHS foot protection or diabetic foot service.

Steps to Lower Your HbA1c and Improve Blood Sugar Control

Lowering HbA1c from 114 mmol/mol requires a combination of medication review or intensification, dietary changes, regular physical activity, and structured self-monitoring, ideally supported by a diabetes care team.

Bringing an HbA1c of 114 mmol/mol down to a safer range is achievable with a structured, multi-faceted approach. Improvement typically requires a combination of medication review, dietary changes, physical activity, and ongoing monitoring, ideally supported by a diabetes care team.

Medication and clinical review Your GP or diabetes specialist will review your current treatment regimen and consider intensifying therapy based on your diabetes type and individual circumstances.

• Type 2 diabetes: NICE NG28 supports the addition or intensification of glucose-lowering agents. Options may include starting or adjusting insulin, adding an SGLT-2 inhibitor (such as empagliflozin or dapagliflozin) or a GLP-1 receptor agonist (such as semaglutide or liraglutide), subject to individual suitability and licensing. These drug classes have evidence-based benefits not only for glucose lowering but also for cardiovascular and renal protection. NICE also supports structured weight management and, in selected adults with type 2 diabetes, a supervised low-calorie dietary programme as part of a remission pathway.

• Type 1 diabetes: Management centres on insulin optimisation under specialist supervision. SGLT-2 inhibitors and GLP-1 receptor agonists are not currently licensed for routine use in type 1 diabetes in the UK and should not be started without specialist guidance. Your diabetes team will advise on the most appropriate insulin regimen and whether CGM or an insulin pump is suitable.

Dietary changes A lower-carbohydrate diet, Mediterranean-style eating pattern, or — for carefully selected adults with type 2 diabetes under clinical supervision — a structured very-low-calorie diet can all contribute meaningfully to HbA1c reduction. Reducing intake of refined sugars, sugary drinks, white bread, and processed foods is a practical starting point. Referral to a registered dietitian is recommended for personalised guidance. If you use insulin or a sulfonylurea, discuss any significant dietary changes with your clinical team first, as dose adjustments may be needed to avoid hypoglycaemia.

Physical activity Regular aerobic exercise — such as brisk walking, cycling, or swimming for at least 150 minutes per week — improves insulin sensitivity and helps lower blood glucose. Even modest increases in daily movement can have a measurable impact on HbA1c over time. Again, if you take insulin or certain other diabetes medicines, speak to your team about adjusting doses around exercise to reduce hypoglycaemia risk.

Wider cardiometabolic risk management NICE recommends that people with diabetes also address other cardiovascular risk factors, including blood pressure control, statin therapy where indicated, and smoking cessation. Your GP or diabetes team can review these alongside your glucose management.

Self-monitoring and education Regular blood glucose self-monitoring or CGM, where appropriate, helps identify patterns and triggers. Structured education programmes such as DESMOND (for type 2 diabetes) or DAFNE (for type 1 diabetes) are recommended by NICE and can significantly improve self-management skills and outcomes. Ask your GP or diabetes team about referral to these programmes.

When to Seek Urgent Medical Advice About Your HbA1c

An HbA1c of 114 mmol/mol warrants a same-week GP or specialist appointment; call 999 or attend A&E immediately if you experience loss of consciousness, chest pain, signs of stroke, or severe vomiting with high ketones.

An HbA1c of 114 mmol/mol should always prompt a prompt appointment with your GP or diabetes care team — this is not a result to monitor passively or delay acting upon. However, there are specific circumstances in which you should seek urgent or emergency medical attention rather than waiting for a routine appointment.

Check your blood or urine ketones if your blood glucose is persistently above 13–14 mmol/L, or if you feel unwell with any of the symptoms below. If capillary blood ketones are 1.5 mmol/L or above (or urine ketones are 2+ or above), seek urgent medical assessment the same day — do not wait.

Contact your GP urgently or call NHS 111 if you experience:

• Persistent vomiting or inability to keep fluids down

• Rapid or laboured breathing

• Confusion, drowsiness, or difficulty staying awake

• Fruity or acetone-smelling breath (a possible sign of DKA)

• Blood glucose readings consistently above 15–20 mmol/L despite medication, particularly if ketones are present

• Signs of a urinary tract or other infection that is not resolving

Call 999 or go to A&E immediately if you experience:

• Loss of consciousness or extreme confusion

• Chest pain or signs of a heart attack

• Sudden weakness, facial drooping, or speech difficulties (signs of stroke)

• Severe abdominal pain with vomiting (possible DKA or HHS)

Even in the absence of acute symptoms, an HbA1c this high warrants a same-week GP or specialist review to reassess your treatment plan, check for early complications, and arrange appropriate follow-up. Your GP may refer you to a specialist diabetes team, arrange retinal screening, check kidney function and urine albumin, and review your feet. Early intervention at this stage can prevent or significantly delay the development of serious long-term complications. Do not hesitate to advocate for yourself and request timely care.

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