If you have type 2 diabetes, your body gradually stops making enough insulin and becomes less able to use the insulin it does make effectively. With too little insulin, your body cannot absorb glucose from the food you eat and your blood glucose levels rise and become harmful to your health.

Understanding the connection between insulin, blood glucose and your average blood glucose levels over time – also known as HbA_1c – is important for controlling type 2 diabetes.

HbA_1C is a measure of your blood glucose levels over the last two to three months. Your healthcare professional will perform a blood test to measure your HbA_1C and use this to set a target blood glucose range for you.

If you have type 2 diabetes, every 1% drop in HbA_1C reduces your risk of complications.

While it is very important to stay within the target HbA_1C range determined by your diabetes team, it is normal for your blood glucose to fluctuate throughout the day depending on many factors. However, you should avoid letting your blood glucose levels remain above or below the healthy range.

High blood glucose, known as hyperglycaemia or 'hypers', damage your blood vessels. It can reduce the supply of oxygen and nutrient-rich blood to your body's organs and nerves.

Controlling your high blood glucose levels will help you avoid complications like:

• Heart attack
• Stroke 
• Reduced eyesight or blindness
• Kidney disease
• Nerve problems
• Blocked circulation in the feet

Low blood glucose, known as hypoglycaemia or ‘hypos’, occurs when blood glucose levels fall below 4.0mmol/L or 20mmol/mol.

High blood glucose is dangerous in the long-term, but low blood glucose levels can also impact your health.

The way you feel when your blood glucose level is low varies from person to person and may not be the same every time. You will soon learn to recognise your own early warning signs and how to take action.

If you experience any of the following symptoms you could be having a hypo:

• Sweaty
• Dizzy
• Hungry
• Cold
• Faint
• Tired
• Confused
• Irritable

Low blood glucose and its symptoms can be dangerous and you need to know what to do if they happen.

You can experience low blood glucose for many reasons, including if you:

• Delayed or missed meals / snacks or not eating enough carbohydrates (eg. bread, pasta, cereals)
• Exercising more than usual (a hypo may occur anytime up to 24 hrs after vigorous exercise)
• If on insulin treatment:
  • Inaccurate dosing of insulin
  • Taking too much insulin
  • Poor injection technique
  • Not resuspending (mixing) premixed insulins properly
• Breastfeeding
• Too much alcohol - particularly the ‘morning after’
• Hot weather
• Vomiting just after a meal
• Recreational drugs
• Sometimes no obvious reason
• Weight loss

Do not delay in treating your hypo. Ask for help as soon as you can if you need it. Take some sugary food or drink as quickly as possible if you are conscious and can safely swallow. Adults are advised to take 15g of fast acting carbohydrate (unless instructed otherwise).

The following are good options to treat a mild hypo:

• 60mls Lift (previously known as Glucojuice)
• 5 Glucose tablets e.g. Dextro-Energy*
• 1-2 tubes of Glucogel
• 170mls of Lucozade Energy Original*
• 150mls of a Full sugar fizzy drink e.g.* Coke or lemonade ( not diet drinks) – Note: brands of fizzy drinks may change their sugar content so check the labels regularly to ensure you are getting the correct amount of carbohydrate.

Re-check your blood glucose levels after 10–15 minutes and re-treat as above if your blood glucose levels are still less than 4.0 mmol/l. If you are starting to feel better, eat your meal if due or have a small carbohydrate snack e.g. slice of bread, piece of fruit.

If you wake up and believe you have had a night-time hypo, the best way to confirm this is to check your blood glucose levels. If you are having a hypo, then treat it as described above.

Talk to your family and friends in advance about what could happen if your blood sugar goes low and in particular how they can help you if you have a severe hypo. If you have a severe hypo and are unconscious those around you will need to do the following:

• do not give you anything by mouth as you may choke
• place you in the recovery position inject you with glucagon which will temporarily raise your blood glucose levels if glucagon is not available call 112/999 immediately (112 is the emergency number for Europe. Please consult local authorities if residing outside Europe)

For full information about managing and avoiding day and night-time hypos, talk to your doctor or nurse at your next appointment

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