15% off £25 OR 20% off £30


15% off £25 OR 20% off £30


🏷️ Buy 1 Get 1 Free☀️ Summer ShopOffersOffers HubBuy one get one 1/2 priceSave up to 1/2 PriceBuy 1 Get 1 Free25% off Online Only OfferOutletFree gift with purchase1/2 Price2 for £50Short DatedVitamins & SupplementsVitamins & Supplements HubVitamins & Supplements Shop AllCBDShop all CBDCBD OilCBD CapsulesCBD SprayCBD GummiesCollagen & SilicaHair, Skin & NailsShop all Hair, Skin & NailsHair GrowthFunctional MushroomsVitaminsShop all VitaminsMultivitaminsVitamin AVitamin BVitamin CVitamin DVitamin EVitamin KVitamin DrinksMineralsShop all MineralsMagnesiumIronZincCalciumSeleniumChromiumSupplementsShop all SupplementsFibre SupplementsAcidophilus & Friendly BacteriaPeppermint OilGrapeseed ExtractLecithinCollagen & SilicaOmega & Fish OilsPlant Sourced SupplementsSuperfood SupplementsArnicaApple CiderRaspberry KetonesAloe VeraChondroitin & MSMCo Enzyme Q10Evening Primrose OilGarlicGinkgo BilobaGlucosamineGlucomannanSeaweed, Kelps and Aquaceuticals5 HTPSaw palmettoCharcoalWomen's HealthShop all Women's HealthMenopauseMenstrual SupportUrinary Tract HealthPregnancy & ConceptionMen's HealthShop all Men's HealthProstate HealthChildren's HealthConditionShop all ConditionWater RetentionAllergy & Hay Fever CareAnxiety SupportBone & Muscle HealthMuscle Support & Joint PainBrain & Memory SupportWomen's HealthMen's HealthChildren's HealthPain ReliefCold & Immune SupportFatigueDigestive HealthHair, Skin & NailsHeart & CirculationLiver CareMood SupportSexual HealthSleep & RelaxationStress ReliefVisionHerbal & Licensed RemediesShop all Herbal & Licensed RemediesValerianSt John's WortRescue RemedyAgnus CastusAshwagandhaEchinaceaMilk ThistleDevil's ClawGinseng & GuaranaBlack CohoshHomeopathic & Flower RemediesShop all Homeopathic & Flower RemediesRescue RemedyTissue SaltsFlower RemediesHomeopathic RemediesAt-Home TestsVegan Vitamins & SupplementsBuy one get one 1/2 priceBuy 1 Get 1 FreeSave up to 1/2 PriceHolland & BarrettVitabioticsSolgarWeledaNew NordicBioglanBetterYouNatures AidGrass & Co.Nature's WayDairy FreeGluten FreeSesame Seed FreeCelery FreeCereal FreeCrustaceans FreeEgg FreeFish FreeKiwi FreeLupin FreeNew inFood & DrinkFood & Drink HubFood & Drink Shop AllVegan FoodHoney, Jams & SpreadsShop all Honey, Jams & SpreadsManuka HoneyHoneyJams & ChutneysNut ButtersSpreadsPateTeas, Coffee & Hot BeveragesShop all Teas, Coffee & Hot BeveragesCoffee & Coffee SubstitutesMushroom DrinksTeasSuperfood TeasMatcha & Green TeaSleep & Relaxation TeaDried Fruit, Nuts & SeedsShop all Dried Fruit, Nuts & SeedsNutsDried FruitSeedsMixesSuperfoodsShop all SuperfoodsSuperfood PowdersMaca PowderGoji BerriesBaobabMoringa PowderFlaxseedSpirulinaChia SeedsSnacksShop all SnacksProtein BarsLow Calorie SnacksChocolate, Cakes & BiscuitsSavoury SnacksSweet SnacksSnack BarsCrisps & ChipsFlapjacksPopcornFood CupboardShop all Food CupboardHoney, Jams & SpreadsBreakfast CerealsSuperfoodsApple Cider VinegarCondiments & SaucesTinned FoodsRice, Pasta, Pulses & GrainsBreakfast CerealsShop all Breakfast CerealsCereals, Bran & FlakesGranolaMuesliOats & PorridgeBreakfast BarsDrinks & JuicesShop all Drinks & JuicesKombuchaNatural Energy DrinksJuicesSoft DrinksWaterAlcohol Free DrinksCookingShop all CookingCooking IngredientsApple Cider VinegarCondiments & SaucesSoya & Meat AlternativeSoup & Ready MealsRice, Pasta, Pulses & GrainsHerbs, Spices & SeasoningGravy & StockHome BakingShop all Home BakingBaking MixesBreadFlourSweeteners & Sugar AlternativesEgg SubstitutesDairy AlternativesShop all Dairy AlternativesOat, Rice & Hemp DrinksSoya DrinksNut DrinksCoconut DrinksNutritionally Complete FoodBuy one get one 1/2 priceSave up to 1/2 Price25% off Online Only OfferHolland & BarrettNaturyaHeath & HeatherPukkaGrenadeMeridianTwiningsBionaNakdHuelGluten FreeDairy FreeEgg FreeWheat FreeMilk FreeMustard FreeCelery FreeFish FreeSulphites FreeCrustaceans FreeNew inSports NutritionSports Nutrition HubSports Nutrition Shop AllProteinShop all ProteinClear ProteinWhey ProteinMass GainersVegan ProteinDiet ProteinCaseinSports SupplementsShop all Sports SupplementsTestosteroneSports CollagenBars, Drinks & SnacksShop all Bars, Drinks & SnacksEnergy BarsEnergy DrinksProtein BarsProtein ShakesProtein SnacksNutritionally Complete FoodMeal Replacement ShakesPre Workout & EnergyShop all Pre Workout & EnergyPre WorkoutAmino Energy DrinksAmino Energy PowdersIntra WorkoutKetoPost WorkoutAmino AcidsShop all Amino AcidsAmino Energy PowdersAmino Energy DrinksBCAAL-LysineGlutamineCarnitineArginineCreatineShop all CreatineCreatine PowderCreatine CapsulesRehydrationShop all RehydrationElectrolytesEnergy GelsVegan Sports NutritionShop all Vegan Sports NutritionVegan ProteinVegan Protein BarsVegan Pre Workout & EnergyVegan Amino AcidsVegan CreatineSports AccessoriesShop all Sports AccessoriesBottles & ShakersFitness EquipmentFitness GoalShop all Fitness GoalRecoveryMuscle & StrengthLean MuscleEnergy & EnduranceDiet & Weight LossSave up to 1/2 PriceBuy one get one 1/2 price2 for £50Optimum NutritionPE NutritionUSNApplied NutritionGrenadePhDSiSFoodspringHuelYfoodDairy FreeGluten FreeSugar FreeSoya FreeCelery FreeCereal FreeCrustaceans FreeEgg FreeFish FreeKiwi FreeNew inBeautyBeauty HubNatural Beauty Shop AllAromatherapy & HomeShop all Aromatherapy & HomePure Essential OilsBlended Essential OilsBase & Carrier OilsHolisticSkincareShop all SkincarePremium SkincareFace CareBody CareSun CareTanning & BronzingEye CareLip CareFoot CareHand & Nail CareSkin AilmentsSkin OilsCBD BeautyHair Skin & NailsWashing & BathingShop all Washing & BathingShampoo & ConditionerBathing AccessoriesShower Gel & Body WashDeodorantDentalHand WashSoapBath Soak & OilBody ScrubBath Bombs & SaltsFeminine CareIncontinence SupportHair CareShop all Hair CareShampoo & ConditionerHair ColouringHair MasksHair Oil & SerumHair Spray, Gel & MousseHair AccessoriesMother & BabyShop all Mother & BabyBaby Skincare & ToiletriesElectrical WellnessSexual WellnessSave up to 1/2 PriceBuy 1 Get 1 FreeBuy one get one 1/2 priceDr OrganicFaith in NatureWeledaNaturtintTisserandSukinMiaromaQ+AEthiqueSo EcoAlcohol FreeParfum FreeParaben FreeSLS FreePalm Oil FreeGluten FreeCelery FreeCereal FreeCrustaceans FreeEgg FreeNew inCBDWeight ManagementWeight Management HubWeight Management Shop AllFat Burners, Binders & Appetite SuppressantsShop all Fat Burners, Binders & Appetite SuppressantsFat BurnersFat BindersAppetite SuppressantsSlimming TabletsShakes & Weight Management ShotsShop all Shakes & Weight Management ShotsMeal Replacement ShakesDiet ProteinDiet Food & DrinkShop all Diet Food & DrinkDiet FoodLow Calorie SnacksSlimming TeaExercise SupportShop all Exercise SupportFitness EquipmentMeal Replacement ShakesDiet ProteinProtein BarsSave up to 1/2 PriceBuy one get one 1/2 price2 for £50Optimum NutritionGrenadeHolland & BarrettUSNPhDPulsinEat WaterNatures AidNew NordicSlimExpertDairy FreeSugar FreeGluten FreeWheat FreeNew inVeganHealth & WellnessShop all Health & WellnessJoints Bones & MusclesGut HealthHair Skin & NailsStress AnxietySleep & RelaxationBuy one get one 1/2 priceBuy 1 Get 1 FreeSave up to 1/2 PriceHolland & BarrettWeledaVitabioticsDr OrganicSolgarNaturtintOptimum NutritionNew NordicHeath & HeatherBioglanDairy FreeGluten FreeParaben FreeSLS FreeAlcohol FreeParfum FreeSugar FreeWheat FreeSoya FreeEgg FreeNew inShop for your WellnessWomen's HealthMenstrual HealthMenopauseJoints, Bones & MusclesGut HealthHair, Skin & NailsImmunitySleep & RelaxationFood & DietChildren's HealthStress ReliefHealthy HeartEnergyLow Mood & DepressionConcentration & AlertnessEye HealthSexual HealthLearn about WellnessWomen's HealthPeriods & Cycle HealthMenopauseJoints, Bones & MusclesImmunityGut HealthFood & DietSports & FitnessSleep & RelaxationHair Skin & NailsAll articlesHealthFood & nutritionGut healthImmunityJoints, bones & musclesWomen's healthWellnessHair & skinMental wellbeingSeasonalSleep & relaxationSports nutritionRecipesAll recipesGluten freeLow sugarVeganDairy freePodcast

What is blood sugar?

Blood sugar levels
Get a better understanding of what blood sugar levels are, how to stay in control of them, and how glucose impacts your levels by reading this guide.

You may experience high and low blood sugar throughout your day, but do you know what’s causing these fluctuations? If your energy and concentration levels keep crashing, blood sugar fluctuations could be to blame – and you don’t need to have diabetes to experience those highs and lows.

Check out our complete guide to blood sugar for non-diabetics and how you can help rebalance yours.

In this article: What is blood sugar? | How does your body control blood sugar? | What is low blood sugar? | What is high blood sugar? | What are normal blood sugar levels? | What happens if your body can’t control your blood sugar? | How to check your blood sugar at home | The bottom line

What is blood sugar?

What is blood sugar?

Blood sugar, also known as blood glucose, is an important type of sugar found in your blood, and we get it by breaking down carbohydrates found in food and drink.1,2  

Glucose is the primary energy source for all the cells in your body. Your brain, which uses 20% of your energy, needs a constant supply of glucose from your bloodstream to function correctly.2 

How your body controls blood sugar

If you don’t have diabetes, your blood sugar naturally goes up and down during the day and night. So, for example, you’ll usually experience a temporary blood sugar spike after eating a meal. Thanks to the pancreas, the ‘control centre’ for blood glucose, our bodies are usually pretty good at controlling these peaks and troughs.3  

Your pancreas produces two hormones that work in a finely tuned balance to keep blood sugar levels steady: 

  • Insulin – large amounts are released when your blood sugar levels go up, for example, right after a meal, to allow your cells to take up and use glucose in the bloodstream4,5 

  • Glucagon – this is needed when your blood sugar levels drop; it stimulates cells, mainly in the liver, to release stored glucose into your bloodstream to boost energy levels6,7 

What is low blood sugar (hypoglycaemia)?

What is low blood sugar (hypoglycaemia)?

For many of us, it’s simply a long gap between meals or fasting. Drinking too much alcohol or being pregnant can also cause symptoms of low blood sugar, including8

  • hunger
  • tiredness
  • shakiness
  • irritability

Another cause of low blood sugar in people without diabetes is reactive hypoglycaemia, most likely caused by eating a large, carbohydrate-heavy meal. The meal can trigger an overproduction of insulin, forcing a drop in blood sugar.

What is high blood sugar (hyperglycaemia)?

You can experience a rapid rise in blood sugar if you eat foods that score high on the glycaemic index, like white bread, cakes, and biscuits: these are broken down faster into glucose than low-GI foods, leading to a spike in blood sugar.10  

However, people without diabetes are unlikely to experience these symptoms because the pancreas steps in to reduce blood sugar levels.11  

If you have been experiencing the following symptoms of high blood sugar, it’s essential to see your GP to test for diabetes:12

  • unusual thirstiness
  • frequent urination
  • tiredness
  • blurred vision
  • weight loss without trying
  • tummy ache
  • feeling nauseous, or vomiting
  • fruity-smelling breath
What is the average blood sugar range?

Your blood sugar levels will fluctuate throughout the day, spiking after you’ve eaten. For those without diabetes, the normal range of blood sugar levels is13:

  • Between 4 and 6mmol/L before eating a meal
  • Less than 8mmol/L two hours after eating a meal
What happens if your body can’t regulate your blood sugar?

Sometimes, your pancreas cannot regulate blood sugar levels properly, which happens when you have type 1, type 2 diabetes or gestational diabetes.14 

Very rarely, blood sugar regulation can also be affected by:9,12,15

  • Some medications, including anti-malarial quinine, beta-blockers or steroids
  • Certain health conditions, for example, hepatitis, anorexia or bulimia, kidney disorders
  • Hormone deficiencies
How to balance your blood sugar

It’s essential to keep your blood glucose steady, as higher than normal levels and reactive hypoglycaemia are both linked to an increased risk of developing type 2 diabetes.16,17

These tips can help you stay in control:

  • Eat carbohydrates that score low on the glycaemic index – low glycemic carbohydrates such as whole grains, most fruits, pulses, and vegetables are broken down more slowly into glucose for a gradual energy release that helps balance your blood sugar18
  • Eat balanced meals – consume meals that are full of plenty of vegetables, salads, protein, and healthy fat sources. Then add in a moderate amount of your favourite carbohydrates, as suggested above!
  • Exercise regularly – it has been shown to improve your body’s regulation of blood sugar and insulin sensitivity19
  • Manage your stress levels – When we experience stress, our bodies produce hormones like cortisol and adrenaline. These hormones can make it harder for our bodies to regulate insulin, which is why it's important to find ways to manage and reduce stress.20

Scientists have also looked at certain herbs and ingredients , like chromium which is believed to help contribute to the maintenance of normal blood sugar levels.21

How to check your blood sugar at home

How to check your blood sugar at home

If you think your blood sugar is higher or lower than it should be, you could use an at-home kit to test your levels.  

You can use at-home blood sugar test kits to give you an insight into your health and help you understand your levels better. HbA1c test kits measure your average blood sugar level over the last 3 months for a more accurate view of how your blood sugar fluctuates over time. However, it’s always essential to go to your GP for help and advice if you have any questions or concerns.  

Handpicked Content: What is at-home blood testing? 

The bottom line

Your blood sugar is so important for your body and well-being, but it fluctuates daily, and these highs or lows can leave you feeling out of sorts. While there are many reasons for these fluctuations, if you are worried about your blood sugar levels, you should always seek advice from a GP. 

There are also at-home diabetes test kits available, which you can use at home to understand your blood sugar levels. You can even take your results with you to your GP appointments, so they give you medical advice and further insights into what they mean.


Advice is for information only and should not replace medical care. Please check with your GP before trying any interventions. 

Written by Colleen Shannon on February 25, 2019, Reviewed by Dr Sarah Schenker on March 6, 2019 




Related Articles

  • Visa
  • MasterCard
  • PayPal
  • AmericanExpress
  • ApplePay
  • ClearPay
  • AliPay
  • Instagram
  • Pinterest
  • Facebook
  • Twitter
Copyright © Holland & Barrett Retail Limited, 2024. All rights reserved. hollandandbarrett.com is a trading name of Holland & Barrett Retail Limited,. Registered office: Samuel Ryder House, Barling Way, Nuneaton, Warwickshire CV10 7RH. Registered in England: company no. 2758955. Registered VAT no. 211727395.