Version 6.0.0, February 2026. First published June 2016. 001210-NDSS_D. Print Share on Facebook Share on X Key facts Low blood glucose levels or “hypos” can happen if you use insulin or some other types of diabetes medicines. Symptoms of a hypo include feeling shaky or lightheaded, headache, difficulty concentrating, and tingling or numb face. Treat a hypo straight away with fast-acting carbohydrates like jellybeans, glucose tablets or gel, or sweet (not diet) soft drink or juice. If you become drowsy, unable to swallow or unconscious, you should not be given anything by mouth. Let your friends, family and workmates know they should call an ambulance immediately. Be prepared for hypos by carrying a hypo kit with hypo treatment supplies and a blood glucose meter. Related pages Blood glucose monitoring High blood glucose levels (hyperglycaemia) Fear of hypoglycaemia Medicines for diabetes Looking after your mind Find a health service Find a health professional or pharmacy in your area. On this page Causes of low blood glucose levels Symptoms of a hypo How to treat a hypo Severe hypos Be prepared with a hypo treatment kit Hypo awareness When to see a health professional More information and support Causes of low blood glucose levels A low blood glucose level, also called hypoglycaemia or a “hypo”, is when your blood glucose level drops below your target range. For most people with diabetes, this is a level below 4.0 mmol/L. Low blood glucose levels can be caused by: delaying or missing a meal eating less carbohydrate (carb) foods than usual being more active than usual drinking alcohol being sick with vomiting or diarrhoea breastfeeding. Symptoms of a hypo Hypos can affect everyone differently and sometimes your symptoms can change. With time, you will learn how hypos can make your own body feel. You may notice one or more of these symptoms: feeling weak, trembly or shaky sweating feeling lightheaded or dizzy headache finding it hard to concentrate, or behaving differently feeling irritable, teary or crying hunger tingling or numb lips, tongue or cheeks your heart beating fast blurry vision. Act quickly if you have hypo symptoms If you feel any hypo symptoms, check your blood glucose level. A blood glucose level below 4.0 mmol/L is a hypo and must be treated straight away. If you cannot check your blood glucose levels, treat as a hypo anyway. How to treat a hypo It is important to treat a hypo quickly to stop your blood glucose level from dropping even lower. Untreated hypos can be dangerous. First, make sure you are safe. For example, if you are driving, pull over to the side of the road. Then treat your hypo using the following steps. STEP 1: Eat some fast-acting carbohydrates Eat some fast-acting carbohydrates (carbs) to quickly raise your blood glucose levels. For most people with diabetes, 15 g of fast-acting carbs is recommended, for example: 4 glucose tablets 6–7 regular jellybeans or 4 large glucose jellybeans 1 tube of oral glucose gel ½ a can (150 mL) of regular soft drink (not diet or zero sugar) 100 mL of Lucozade® 3 teaspoons of sugar or honey ½ a glass (125 mL) of fruit juice. You may need a different amount or type of fast-acting carbs to treat a hypo, for example, if you are using an insulin pump. Ask your doctor or diabetes health professional what you should have. STEP 2: Check your blood glucose levels again Recheck your blood glucose level after 10 to 15 minutes. If it is above 4 mmol/L, proceed to Step 3. If it is still below 4 mmol/L, repeat Steps 1 and 2. STEP 3: Eat some slow-acting carbs Once your blood glucose level is above 4.0 mmol/L, you may need to eat some slow-acting carbs to sustain your blood glucose level. If your next meal is within 15 to 20 minutes, you can eat this instead. Examples of 15 g of slow-acting carbs include: 1 slice of bread 1 glass (250 mL) of milk or soy milk 1 piece of fruit 4 dried apricots 1 tablespoon of sultanas 1 small tub (100 g) fruit yoghurt. Not everyone needs to eat slow-acting carbs after treating a hypo. Talk to your doctor or diabetes health professional about what is right for you. If you use continuous glucose monitoring Sensor readings can lag behind finger prick blood glucose readings, especially when blood glucose levels are changing quickly. Confirm your glucose level by a finger prick blood glucose check when possible, to accurately treat a hypo. Severe hypoglycaemia If a hypo is not treated, your blood glucose levels will continue to drop. This may lead to severe hypoglycaemia (a severe hypo). A severe hypo is when you need help from someone else to treat the hypo. It is important that your family, friends, and workmates know you have diabetes and what to do in case of a severe hypo. If you have severe hypoglycaemia you might: have slurred speech be confused become unconscious have a seizure. Treating a severe hypo with glucagon Glucagon is used to treat a severe hypo. It is a hormone that rapidly raises the blood glucose levels. Glucagon is available in an injectable pen device. Your doctor, nurse practitioner or diabetes educator may recommend you keep a glucagon injection at home. They may also recommend that you carry it with you when you are away from home in case of a severe hypo. You or your diabetes health professional can show your family or friends how to use a glucagon injectable pen device. If you have a severe hypo, tell your doctor as soon as possible. It is important to try and find the cause and to review your diabetes management plan. You should also discuss when you should return to your normal activities, such as driving. If you become unconscious, drowsy, or unable to swallow Make sure your family, friends, and workmates know they should: Lay you on your side and check your airway is clear. In first aid this is called the recovery position. Not give you anything by mouth. Give you an injection of glucagon if available and they know how. Call 000 for an ambulance and inform them that you are unconscious and have type 1 diabetes. The operator may be able to provide instructions on how to inject glucagon. Stay with you until help arrives. Be prepared with a hypo treatment kit Make a hypo treatment kit to carry with you that contains: Blood glucose meter, strips and lancing device Fast-acting carbohydrates like jellybeans, glucose gels or tablets, or a small juice carton Slow-acting carbohydrates like a muesli bar, dried fruit, or crackers A glucagon injection if recommended by your diabetes health professional Hypo unawareness Some people do not feel the early warning symptoms of a hypo, and some people have no symptoms at all. This can increase the risk of a severe hypo and unconsciousness, and lead to fear of hypoglycaemia. Hypo unawareness is more common in people who have had diabetes for many years. If you have hypos without early symptoms, it’s important to talk to your doctor or diabetes health professional. You may need to check your glucose levels more often. A CGM device can sound an alarm when your glucose levels are low or dropping. Always treat a hypo when your glucose level is below 4.0 mmol/L, even if you have no symptoms. Hypos and driving Check your blood glucose level before driving. Do not drive if it is under 5.0 mmol/L. If you have hypo unawareness or have had a severe hypo, you must talk to your doctor or diabetes health professional before driving. Go to the NDSS Diabetes and driving quick guide for more information. When to see a health professional Make an appointment with your doctor, diabetes educator or diabetes nurse practitioner if you: have hypos often, as your diabetes management plan may need changing have a severe hypo are not sure if you are at risk of hypos, or how to treat them are fearful of hypos and it’s affecting your daily life or diabetes management. What this means for you A low blood glucose level (hypoglycaemia or hypo) is when your blood glucose level drops below 4 mmol/L. If you have a hypo, treat it straight away with fast-acting carbohydrates to avoid a severe hypo. Make sure your family, friends and school or workmates know what to do if you have a severe hypo. Be prepared by carrying a hypo kit with you, knowing what causes hypos, and how to recognise one. More information and support Call the NDSS Helpline on 1800 637 700 to ask to speak to a diabetes educator Find a credentialled diabetes educator: Go to the Australian Diabetes Educators Association website to find a credentialled diabetes educator near you. Get peer support: Visit the NDSS Peer Support website to learn about peer support, read about others living with diabetes, or search the directory of online and face-to-face peer support groups across Australia. Disclaimer This information is intended as a guide only. It should not replace individual medical advice and if you have any concerns about your health or further questions, you should contact your health professional. Sources Healthdirect. Hypoglycaemia (Low blood sugar) (2024). Royal Australian College of General Practitioners (RACGP). Management of type 2 diabetes: A handbook for general practice. Managing glycaemic emergencies (2024). The Management of Type 1 Diabetes in Adults. A Consensus Report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) (2021). Australasian Paediatric Endocrine Group (APEG) and Australian Diabetes Society. National evidence-based clinical care guidelines for type 1 diabetes in children, adolescents and adults (2011).
