A salad, a glass of water, running shoes and a glucose meter on a kitchen counter

Blood Sugar Support: Blood Glucose Levels Chart and Daily Habits

Key Takeaways

  • "Blood sugar support" is a search phrase, not a clinical term. The ADA describes seven things instead: education, nutrition, activity, sleep, no tobacco, behaviour counselling and psychological care.[1]
  • On the ADA chart, a fasting result below 100 mg/dL (5.6 mmol/L) is normal, 100 to 125 mg/dL (5.6 to 6.9 mmol/L) is prediabetes and 126 mg/dL (7.0 mmol/L) or higher is diabetes. A diagnosis usually needs a repeat test.[2][3]
  • Targets for people with diabetes are different numbers and are set with your care team. The ADA suggests 80 to 130 mg/dL (4.4 to 7.2 mmol/L) before meals. For adults with type 1, the NHS and NICE suggest 5 to 7 mmol/L (90 to 126 mg/dL) on waking, 4 to 7 mmol/L (72 to 126 mg/dL) before other meals and 5 to 9 mmol/L (90 to 162 mg/dL) at least 90 minutes after eating.[4][5][6]
  • Checking alone does not change your glucose. The ADA says performing blood glucose monitoring alone does not reduce blood glucose levels; the numbers have to feed into a plan.[7]
  • In the UK a low is usually below 4 mmol/L (72 mg/dL); in the US it is below 70 mg/dL (3.9 mmol/L). These are close but not the same line. Each country has its own emergency rules, listed below.[8][2]

Type "blood sugar support" into a search engine and you get supplement adverts, a few charts and a lot of advice with no source. This guide does something simpler. It puts the official blood glucose levels chart in both units, mg/dL for US readers and mmol/L for UK readers. Next to it sit the targets the ADA, NICE and the NHS set for people who already have diabetes. Then it goes through the daily habits those bodies actually recommend, how often to check, and the exact signs that mean you should call your GP, 999 or 911.

Every guideline number here comes from the 2026 ADA Standards of Care, NICE, the NHS, the NIDDK or Diabetes UK, and each source is linked at the end. Where we cite a study, we say who paid for it when the record shows it.

This guide is general education. If you use insulin or other glucose medicines, follow the plan your diabetes team gave you.

What does "blood sugar support" mean?

No guideline uses the phrase. We looked in the 2026 ADA Standards of Care, the NICE guidelines and the NHS pages and found nothing under that name. What the ADA does list, in its section on health behaviours, is a set of seven things it calls essential. They are diabetes self-management education and support, medical nutrition therapy, routine physical activity, adequate quality sleep, support to stop tobacco and vaping, health behaviour counselling, and psychosocial care.[1] That list is what the rest of this guide follows.

In plain words, blood sugar support means the habits, the checks and the care plan that keep your readings in the range your team set. It is not a product, and it is not something you can buy in a bottle. Diabetes UK adds one point: not everyone with diabetes needs to check their levels at home. You will need to if you take certain diabetes medicines.[9]

Blood glucose levels chart: normal, prediabetes and diabetes

These are the normal blood sugar levels and the diagnostic cut-offs for people who have not been diagnosed. They come from the ADA's 2026 classification and its consumer diagnosis page.[3][2] The NHS high blood sugar page uses the same HbA1c line, 48 mmol/mol, which is 6.5%, and counts a fasting test over 7 mmol/L (126 mg/dL) as high.[10]

Test. Normal. Prediabetes. Diabetes.
Fasting glucose, at least 8 hours with nothing but water. Below 100 mg/dL (below 5.6 mmol/L).[2] 100 to 125 mg/dL (5.6 to 6.9 mmol/L).[3] 126 mg/dL (7.0 mmol/L) or higher.[3]
Two hours after a 75 g (about 2.6 oz) glucose drink, lab test. Below 140 mg/dL (below 7.8 mmol/L).[2] 140 to 199 mg/dL (7.8 to 11.0 mmol/L).[3] 200 mg/dL (11.1 mmol/L) or higher.[3]
A1C (HbA1c), a 2 to 3 month average. Below 5.7% (below 39 mmol/mol).[2] 5.7% to 6.4% (39 to 47 mmol/mol).[3] 6.5% (48 mmol/mol) or higher.[3]
Random glucose, any time. Not used for diagnosis.[3] Not used for diagnosis.[3] 200 mg/dL (11.1 mmol/L) or higher with classic symptoms.[3]

Four notes on reading it. First, the two hour row is a lab test with a measured glucose drink, not a home reading after lunch.[3] Second, no source we read gives a bottom figure for the normal column, so we have not printed one. Third, the ADA says a diagnosis usually needs the test repeated on a second day, unless glucose is unmistakably high.[2][3] Fourth, the ADA notes that the World Health Organization and several diabetes bodies start the prediabetes fasting range at 110 mg/dL (6.1 mmol/L) rather than 100 mg/dL (5.6 mmol/L). So the prediabetes label can depend on where you live.[3]

The ADA also writes that for all three tests, risk is continuous, extending below the bottom end of the range.[3] A reading just under a cut-off is not a pass mark. If you have prediabetes, the ADA says to be checked for type 2 diabetes every one to two years.[2]

Targets for people with diabetes

Once you have a diagnosis, the chart above stops being the goal. Targets are different numbers, and the ADA says they must be woven into an individualized, person-centered strategy.[4] The NHS says the same in fewer words: these blood sugar levels are a guide, and your levels may be different depending on your age and the type of diabetes you have.[10]

Measure. ADA, most nonpregnant adults. UK, adults with type 1.
A1C (HbA1c). Below 7% (53 mmol/mol) for many adults without problem lows.[4] 48 mmol/mol (6.5%) or below.[6] For type 2: 48 mmol/mol (6.5%) on diet or medicines that do not cause lows, 53 mmol/mol (7.0%) on a medicine that can.[11]
On waking, before eating. 80 to 130 mg/dL (4.4 to 7.2 mmol/L), as part of the before-meal target.[4] 5 to 7 mmol/L (90 to 126 mg/dL).[6][5]
Before other meals. 80 to 130 mg/dL (4.4 to 7.2 mmol/L).[4] 4 to 7 mmol/L (72 to 126 mg/dL).[6][5]
After meals. Peak below 180 mg/dL (10.0 mmol/L).[4] 5 to 9 mmol/L (90 to 162 mg/dL) at least 90 minutes after eating, if you choose to test then.[6][5]
Too low. Below 70 mg/dL (3.9 mmol/L).[4] Usually below 4 mmol/L (72 mg/dL).[5]

Two gaps are worth knowing. NICE gives no finger prick targets for adults with type 2 diabetes, only an HbA1c target, and Diabetes UK says so outright.[11][9] And the NHS "high" cut-offs, over 7 mmol/L (126 mg/dL) before eating and over 11 mmol/L (198 mg/dL) at least 90 minutes after, are warning lines, not targets.[10] The NIDDK puts the common US range at 70 to 180 mg/dL (3.9 to 10.0 mmol/L).[12] Our HbA1c guide explains what the 3 month average measures.

Daily habits the guidelines name

Five habits, each one taken from an ADA or NHS recommendation, with the one study type we could find for sleep and water.

Food

The ADA tells clinicians to emphasize minimally processed, nutrient dense, high fibre sources of carbohydrate, with at least 14 g (0.5 oz) of fibre per 1,000 kcal.[1] It says to replace sugar sweetened drinks, including any juices, with water or no calorie drinks and to minimise foods with added sugar.[1] It also says that for some adults, reducing carbohydrate intake is worth considering, and that limiting processed foods is an effective way to do it.[1]

The NHS list for type 2 is similar: fruit, vegetables, wholegrain foods such as wholemeal bread and oats, and pulses such as chickpeas and lentils. It adds not too much processed food with lots of salt and sugar.[5] The NHS adds one line on the same page: do not stop taking your medicine unless your healthcare professional or doctor tells you to.[5]

Movement

The number is weekly, not daily. The ADA counsels most adults with type 1 and type 2 diabetes to do 150 minutes or more of moderate to vigorous aerobic activity a week. It should be spread over at least 3 days, with no more than 2 days in a row without activity. Fitter people may manage with 75 minutes of vigorous activity.[1] It adds 2 to 3 resistance sessions a week on non consecutive days, and says prolonged sitting should be interrupted at least every 30 minutes.[1]

The NHS gives the same 150 minutes, spread over 4 to 5 days or every day, with strength work on at least 2 days. Its intensity test is simple: you can still talk, but not sing.[5] Our exercise guide has more.

Sleep

The ADA tells clinicians to screen for sleep health in people with diabetes, at grade B. It also tells them to counsel sleep promoting routines, at grade A, its top evidence grade. It says sleep disorders are a risk factor for developing type 2 diabetes and that poor sleep is reported by 30% to 50% of people with type 1.[1] The NIDDK suggests about 7 to 8 hours a night.[12]

The cohort evidence is consistent on the shape but shows association only. A pooled analysis of 10 cohort studies with 482,502 people found the lowest rate of new type 2 diabetes at 7 to 8 hours. The relative risk was changed by about 9% for each hour under 7 and about 14% for each hour over.[13] An earlier pool of 10 cohorts with 107,756 people found both short sleep and long sleep linked with more new cases, and trouble staying asleep linked most strongly of all.[14] People reported their own sleep in both, and neither shows that sleeping longer changes tomorrow's reading. Our sleep guide goes deeper.

Stress

Stress and diabetes distress are not the same thing. The NHS lists feeling stressed, along with being unwell, as a cause of a high reading.[10] Separately, the ADA describes diabetes distress, the emotional burden of living with a demanding condition. It says this affects more than 60% of people with type 2 and more than 70% of people with type 1. It asks clinicians to screen for it at least once a year and names brief coping strategies such as mindful breathing and cognitive reframing.[1]

We found no trial in these sources showing that a relaxation technique changes a glucose reading, so we do not claim one. The NHS advice is simply to try to find ways to manage stress.[10] Our stress guide covers the link in more detail.

Water

The ADA's recommendation is to consume water over other beverages, at its top evidence grade.[1] One French cohort followed 3,615 adults with normal fasting glucose for 9 years. Those who reported drinking 0.5 to 1 litre (about 17 to 34 fl oz) of water a day were less often found with a new high fasting glucose than those under 0.5 litres (about 17 fl oz), with an odds ratio of 0.68. The authors wrote that the study does not establish causality, and it was co-funded by several drug companies.[15] You may have read that water helps the kidneys flush sugar out. We found no source for that claim, so it is not in this guide. Our hydration guide sticks to what is sourced.

How often should you check?

There is no single number. It depends on the medicines you take, and the ADA says the specific needs and goals of the person with diabetes should dictate frequency and timing.[7]

On insulin: NICE and the NHS tell adults with type 1 to check at least 4 times a day, including before each meal and before bed. NICE supports up to 10 times a day in some situations.[6][5] The ADA says that for many people on intensive insulin using a meter alone, this means finger sticks 6 to 10 times a day.[7] It lists the moments. Fasting, before meals and snacks, after meals, at bedtime and in the middle of the night. Around exercise, when a low or a high is suspected, and after a low until glucose is back in range. Before and during critical tasks such as driving.[7]

Type 2 without insulin: NICE says not to routinely offer self monitoring unless one of four things applies. You are on insulin, there is evidence of lows, you take a tablet that can cause lows (such as a sulfonylurea like gliclazide or glimepiride) while driving or operating machinery, or you are pregnant or planning to be.[11] The ADA says checking in people on non insulin medicines has not consistently shown clinically significant changes in A1C (HbA1c), though it may help when changing meals, activity or medicines.[7] The ADA's warning applies to everyone: performing blood glucose monitoring alone does not reduce blood glucose levels. To be useful, the information must be integrated into a plan.[7]

Driving in the UK: the NHS says that if you drive, you need to check before each journey and then every 2 hours while driving.[8] When unwell, exercising or drinking alcohol, check more often.[5] HbA1c is checked every 3 to 6 months until it is stable, then every 6 months.[11][5] If you use a sensor, Diabetes UK notes that its readings can lag a finger prick by up to 15 minutes.[9] One more ADA line: never buy or resell second hand test strips, as they may give incorrect results.[7] Our guide to self monitoring walks through the meter itself.

When to call your GP, 999 or 911

The UK and US lines differ, so each sign below carries its own country.

Low blood sugar

In the UK, the NHS says a hypo is usually below 4 mmol/L (72 mg/dL).[8] In the US, the ADA says low blood glucose is below 70 mg/dL (3.9 mmol/L), and it grades lows in three levels. Level 1 is below 70 mg/dL (3.9 mmol/L). Level 2 is below 54 mg/dL (3.0 mmol/L). Level 3 is any event where you need another person's help to recover.[4][2] The NHS symptom list is feeling hungry, dizzy, anxious or irritable, sweating, shaking, tingling lips, palpitations, feeling tired or weak, blurred vision and confusion. A severe low can cause a seizure or unconsciousness.[8]

If you are conscious, both bodies say to take fast glucose. The ADA says glucose is the preferred choice, to avoid foods high in fat or protein for the first step, and to repeat after 15 minutes if you are still low.[4] The NHS says to check again after 10 to 15 minutes, and never to give food or drink to someone who is unconscious, because they cannot swallow safely.[8] Our guide to low blood sugar covers the warning signs in full.

In the UK, the NHS says to call 999 if someone may have very low blood sugar and is not responding normally or is unconscious, and a glucagon injection is not available or you do not know how to use it, or they have not recovered within 10 minutes of a glucagon injection, or they have been drinking alcohol.[8] In the US, the ADA says to call 911 immediately if someone is unconscious and glucagon is not available or no one knows how to use it.[2] See a GP, the NHS adds, if you get hypos often, have had a severe one or one at night, or do not always recognise the symptoms.[8]

High blood sugar and ketoacidosis

The NHS symptoms of a high are feeling very thirsty, peeing a lot, feeling weak or tired, blurred vision and losing weight.[10] Speak to your care team or GP if the level stays high after you have followed your plan, or if you have these symptoms and have not been diagnosed.[10]

Diabetic ketoacidosis is different. It happens when a lack of insulin lets ketones build up. It usually affects people with type 1 but can affect people with type 2 who need insulin, and the NHS says it needs urgent hospital care. Symptoms usually build over 24 hours but can be faster.[10]

The NHS says to call 999 or go to A&E if you think you have high blood sugar and any of these apply.[10] You are feeling sick, being sick or have stomach pain. You are breathing more quickly or your heart is beating faster than usual. You feel drowsy or are struggling to stay awake. Your breath smells fruity, like pear drop sweets. You feel confused. Or you have a high level of ketones in your blood or pee.[10] This list is from NHS pages. In the US the emergency number is 911. Do not drive to A&E, and do not stop taking insulin, even if you are not eating.[10]

If you have a blood ketone meter, the NHS gives four bands. Under 0.6 mmol/L (under 6.2 mg/dL) is normal. From 0.6 to 1.5 mmol/L (6.2 to 15.6 mg/dL) is slightly high and the NHS says to test again in 2 hours. From 1.6 to 3 mmol/L (16.6 to 31.2 mg/dL) you are at risk and should speak to your care team. Over 3 mmol/L (over 31.2 mg/dL) you may have ketoacidosis and should call 999 or go to A&E. On urine strips, over 2+ is high.[10]

How to start

  1. Ask your care team which chart applies to you: the diagnostic chart, or targets for someone with a diagnosis.[4]
  2. Write your own targets down in your unit, mg/dL or mmol/L, and keep them on your phone.[4]
  3. Ask how often to check, and at which moments. The answer is different on insulin than off it.[7][11]
  4. Pick one habit from the list above for the first month. The ADA's list starts with education, not with food.[1]
  5. Learn the low and high emergency signs for your country and tell someone who lives with you.[8][2]
Pro Tip

Keep both units on your chart even if you only use one. UK and US pages do not share a hypo line, 4 mmol/L (72 mg/dL) and 70 mg/dL (3.9 mmol/L) are not the same number, and the ADA pages and papers use mg/dL first.[8][2]

Questions to ask your diabetes team

  • What are my personal targets before and after meals, and for HbA1c?[4][11]
  • Do I need to check at home at all, and if so, how many times a day?[11][9]
  • Which of my medicines can cause a low?[8]
  • Should I keep ketone strips at home, and at what reading should I call?[10]

Frequently asked questions

What is a normal blood sugar level?

On the ADA chart, a fasting result below 100 mg/dL (5.6 mmol/L) and an A1C (HbA1c) below 5.7% (39 mmol/mol) are in the normal column. Two hours after a 75 g (about 2.6 oz) glucose drink in a lab test, normal is below 140 mg/dL (7.8 mmol/L). No source we read gives a bottom figure for normal fasting glucose, so we do not print one.[2][3]

Can a home meter or a CGM diagnose diabetes?

No. Diabetes UK says sensors sold to people without diabetes cannot be used to diagnose diabetes or prediabetes, and that diagnosis can only be done by blood tests your GP arranges.[9] The ADA says there is not enough evidence to use continuous glucose monitoring for screening or diagnosis, and that a diagnosis usually needs a repeat test on a second day.[3][2]

What are the blood sugar targets in pregnancy?

Diabetes UK lists fasting below 5.3 mmol/L (95 mg/dL), one hour after meals below 7.8 mmol/L (140 mg/dL) and two hours after meals below 6.4 mmol/L (115 mg/dL).[9] Pregnancy targets are set by your maternity and diabetes team, so use these as a guide only.[9]

What is the 15/15 rule?

It is the ADA's rule for a low: take 15 g (0.5 oz) of fast-acting carbohydrate, wait 15 minutes, then check again and repeat if you are still below 70 mg/dL (3.9 mmol/L).[2][4] The NHS gives a similar list for the UK: a small glass of fruit juice or sugary fizzy drink, 5 glucose tablets, 4 large jelly babies or 2 tubes of glucose gel. Then it says to recheck after 10 to 15 minutes.[8]

Is one slightly high reading a problem?

Usually not. The NHS says it is not usually a serious problem if your blood sugar is sometimes slightly high for a short time. It is a problem when it stays high, when you have symptoms, or when ketones appear.[10]

Where to go next

A chart gives you the lines, and these related guides cover the habits and tests that sit around them:

Note: If you are pregnant, breastfeeding, or considering giving any supplement or herbal product to a child, consult your healthcare provider before making any changes to your diet, supplement routine, or prescribed medications.

Disclaimer: These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Talk to your doctor before changing your diet, your activity or your medicines, and before starting any supplement.

Sources & References

  1. American Diabetes Association Professional Practice Committee (2026). 5. Facilitating Positive Health Behaviors and Well-being to Improve Health Outcomes: Standards of Care in Diabetes-2026. Diabetes Care. Committee disclosures are published separately by the ADA. pubmed.ncbi.nlm.nih.gov/41358898
  2. American Diabetes Association (consumer pages, undated). Diabetes Diagnosis; Check Your Blood Glucose; Hypoglycemia (Low Blood Glucose). Patient pages of a US charity; they show no review date. Checked 25 October 2026. diabetes.org
  3. American Diabetes Association Professional Practice Committee (2026). 2. Diagnosis and Classification of Diabetes: Standards of Care in Diabetes-2026. Diabetes Care. Committee disclosures are published separately by the ADA. pubmed.ncbi.nlm.nih.gov/41358893
  4. American Diabetes Association Professional Practice Committee (2026). 6. Glycemic Goals, Hypoglycemia, and Hyperglycemic Crises: Standards of Care in Diabetes-2026. Diabetes Care. Committee disclosures are published separately by the ADA. pubmed.ncbi.nlm.nih.gov/41358894
  5. NHS (pages last reviewed 31 October 2024, 10 February 2025 and 22 May 2024). Type 1 diabetes: managing blood glucose levels; Type 2 diabetes: food and keeping active; Physical activity guidelines for adults aged 19 to 64. Checked 25 October 2026. nhs.uk
  6. National Institute for Health and Care Excellence (recommendations dated 2015, some amended 2022). Type 1 diabetes in adults: diagnosis and management (NG17), recommendations. The glucose target recommendations are dated 2015. Checked 25 October 2026. nice.org.uk
  7. American Diabetes Association Professional Practice Committee (2026). 7. Diabetes Technology: Standards of Care in Diabetes-2026. Diabetes Care. Committee disclosures are published separately by the ADA. pubmed.ncbi.nlm.nih.gov/41358889
  8. NHS (page last reviewed 3 August 2023). Low blood sugar (hypoglycaemia). Due for review in August 2026 and still the live version when we checked. Checked 25 October 2026. nhs.uk
  9. Diabetes UK (page reviewed 6 October 2026). How to check your blood sugar levels. Charity page. Checked 25 October 2026. diabetes.org.uk
  10. NHS (pages last reviewed 17 March 2026 and 8 June 2023). High blood sugar (hyperglycaemia); Diabetic ketoacidosis. The ketoacidosis page was due for review in June 2026 and was still the live version when we checked. Checked 25 October 2026. nhs.uk
  11. National Institute for Health and Care Excellence (2015, last updated 18 February 2026). Type 2 diabetes in adults: management (NG28), recommendations. The HbA1c target recommendation was amended in 2026; the self-monitoring recommendations are dated 2015, amended 2022. Checked 25 October 2026. nice.org.uk
  12. National Institute of Diabetes and Digestive and Kidney Diseases (page last reviewed October 2023). Managing Diabetes. US government institute page. Checked 25 October 2026. niddk.nih.gov
  13. Shan Z, Ma H, Xie M, et al. (2015). Sleep duration and risk of type 2 diabetes: a meta-analysis of prospective studies. Diabetes Care. Pooled 10 cohort studies with 482,502 people; self-reported sleep. Funding and conflicts of interest not stated in the PubMed record; full text not checked. pubmed.ncbi.nlm.nih.gov/25715415
  14. Cappuccio FP, D'Elia L, Strazzullo P, Miller MA (2010). Quantity and quality of sleep and incidence of type 2 diabetes: a systematic review and meta-analysis. Diabetes Care. Pooled 10 cohort studies with 107,756 people; self-reported sleep. Supported in part by a European Commission grant. The authors reported no conflicts of interest. pubmed.ncbi.nlm.nih.gov/19910503
  15. Roussel R, Fezeu L, Bouby N, et al.; D.E.S.I.R. Study Group (2011). Low water intake and risk for new-onset hyperglycemia. Diabetes Care. One French cohort of 3,615 adults followed for 9 years; self-reported water intake. The D.E.S.I.R. study was financed by INSERM contracts with the French health insurance fund and several drug companies, including Lilly, Novartis, sanofi-aventis and Novo Nordisk; the authors say these had no role in the study. pubmed.ncbi.nlm.nih.gov/21994426
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