What should my blood sugar be with diabetes?
Usually 4 to 7 before meals. Below 4 is a hypo. But with type 2, your GP watches a different number most, and its aim depends on your medicine.
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What are normal blood sugar levels for a diabetic?
Before meals, a finger-prick reading of 4 to 7 mmol/L is the usual guide. The NHS calls a home test over 7 on waking or before eating high.
After a meal, a home test over 11 is high, if you check at least 90 minutes after eating. Below 4 is usually a hypo (low blood sugar), and it needs treating quickly.
- Below 4 mmol/LHypo. Treat it now.
- 4 up to 7 mmol/LUsual guide before meals.
- Above 7 mmol/LNHS: high before meals.
Sources: NHS: high blood sugar; NHS: low blood sugar; Diabetes UK
Think of 4 to 7 as your lane: drifting out for a moment isn’t a crash. The NHS says being slightly high for a short time isn’t usually serious.
Staying high for a long time, or getting very high, is the danger. It can lead to damage to your nerves and eyes, and to heart disease and stroke.
These numbers are a guide, and yours may be different because of your age and type of diabetes. Don’t know your own range? Ask your diabetes team at your next appointment.
What should type 2 diabetes blood sugar levels be?
There’s no official finger-prick target for type 2. Diabetes UK says NICE has no recommendations for one, so your care team agrees yours with you.
Many people with type 2 don’t test at home at all. NICE says finger-prick checks aren’t routinely offered unless you:
- take insulin
- have had hypos
- take tablets that may raise your hypo risk while driving or using machinery
- are pregnant or planning a pregnancy
That different number is your HbA1c. It’s a blood test of your average sugar over the last 2 or 3 months.
| Your situation | HbA1c aim (mmol/mol) | What the guidance says |
|---|---|---|
| Diet and activity, or a first medicine that doesn’t cause hypos | 48 (6.5%) | Support you to aim for 48. |
| A medicine that can cause hypos, such as insulin or gliclazide | 53 (7.0%) | Support you to aim for 53. |
| Your HbA1c rises to 58 (7.5%) or more on your first medicines | 53 (7.0%) | Step up your medicines, plus diet and lifestyle support. |
| Older or frailer, at risk of falls, or you drive for work | May be relaxed | NICE: consider a less strict aim, case by case, with you. Diabetes UK: a fall from a hypo may be a bigger risk. |
Sources: NICE NG28; Diabetes UK: HbA1c; NHS: low blood sugar
Below your aim with no hypos? NICE says keep it there. A low HbA1c can have other causes, so your team may check why.
NICE advises an HbA1c test every 3 to 6 months until it’s stable, then every 6 months. More on the HbA1c test and how to lower it.
Never stop or change a prescribed medicine without your prescriber.
What are type 1 diabetes blood sugar levels?
Type 1 does have finger-prick targets. They come from NICE for adults and Diabetes UK for children.
| When | Adults | Children |
|---|---|---|
| On waking | 5 to 7 | 4 to 7 |
| Before other meals | 4 to 7 | 4 to 7 |
| After meals | 5 to 9, at least 90 minutes after eating | 5 to 9 |
Sources: NICE NG17; Diabetes UK
NICE also suggests adults aim for an HbA1c of 48 or lower, as long as it doesn’t bring problem hypos. Adults should agree a bedtime target with their team too.
Pregnant with any type of diabetes? Aim for below 5.3 fasting and below 7.8 one hour after meals, or below 6.4 at two hours. Stay above 4.
Your own targets may be different. Your diabetes team will agree them with you, so ask at your next review.
What is a target glucose range on a CGM?
A CGM is a small sensor under your skin that reads your sugar day and night. Its app shows your time in range.
Most diabetes experts say to aim for 3.9 to 10 mmol/L for at least 70% of the day. Your type of diabetes, age, pregnancy and other conditions can change that.
Source: Diabetes UK: time in range
HbA1c is like your average speed on a long drive. Time in range shows how much of the drive you spent inside the limits.
An average can’t show the swings, and time in range doesn’t replace the average. Diabetes UK says time in range is not a replacement for HbA1c, and your team can use both.
Wear a CGM? Share your time in range with your team before each review. See CGM vs HbA1c for how the two compare.
What should I do if my blood sugar is too low or too high?
Below 4? The NHS steps
- 1
Sugar, fast
A small glass of juice, 5 glucose tablets or 4 large jelly babies.
- 2
Check again
Test after 10 to 15 minutes.
- 3
Still below 4?
Have more sugar and check after 10 minutes.
- 4
Back above 4
Eat biscuits, a sandwich or your next meal.
Source: NHS: low blood sugar
Driving? The NHS says check before each journey and every 2 hours on the road. After a hypo, wait at least 45 minutes once your sugar is back to normal.
Six NHS ways to keep high blood sugar down
- Take your diabetes medicine as your doctor or care team advised.
- Avoid eating too much sugary or starchy food.
- Find ways to manage stress.
- Exercise regularly.
- Lose weight if you’re overweight.
- Follow your care team’s advice for when you’re ill, called sick day rules.
Source: NHS: high blood sugar
Being ill, stressed or less active can all push your sugar up. So can steroid medicines. One easy habit to try is a walk after meals.
When to speak to a GP
A sugar just above your target usually causes no symptoms. So the numbers are your best guide. Speak to your care team or GP if:
- You’ve tried to lower your sugar but it’s still high, or you still have symptoms.
- You get hypos often, have had a severe hypo or get hypos at night, or you don’t always notice the signs of one.
- You have signs of high sugar, like thirst, peeing a lot or feeling tired, and haven’t been diagnosed with diabetes.
- Call 999 or go to A&E if your sugar may be high and you feel or are sick, or have stomach pain. Also call if you’re breathing faster than usual or your heart is beating faster than usual. Or if you feel drowsy or are struggling to stay awake, or you feel confused or find it hard to concentrate. Or if your breath smells fruity (like pear drops), or a blood or pee test shows high ketones. High ketones are a sign of a serious problem called diabetic ketoacidosis.
- Someone with very low sugar is unconscious or not responding normally? Call 999 if a glucagon injection (an emergency jab that raises blood sugar) isn’t to hand or you don’t know how to use it. Also call if it hasn’t worked within 10 minutes, or they’ve been drinking.
Don’t drive yourself to A&E. Ask someone to drive you, or call 999.
Not sure if you have diabetes? See the glucose blood test.