A high blood glucose (sugar) level first thing in the morning can be very confusing. Especially if you have been taking your diabetes medication and following your dietary plan.
Here we explain some of the reasons why morning blood glucose levels can be high, and provide tips from experts for the best way to avoid and/or control them.
1. Natural hormone cycles increase blood sugar levels
Many hormones are released in a natural daily cycle, or circadian rhythm. This rhythm is responsible for the changes in our body that occur roughly every 24 hours – such as our sleep-wake patterns, changes in hunger and body temperature, and when we feel most energised and alert. The early morning rise in blood glucose is part of this normal daily rhythm.
Glucose is used by cells in the body as the main source of energy. By increasing the supply of glucose first thing in the morning, your body becomes prepared for the day ahead.
The morning rise in glucose is caused by increased levels of other hormones in the morning, including cortisol and glucagon. One of the main roles of both cortisol and glucagon is to signal the liver to start turning its stores of glycogen into glucose. This glucose is released into the blood – increasing your blood glucose levels.
In most people, this rise in glucose is counteracted by the production of another hormone, insulin, that keeps blood glucose levels in a normal range. This early morning rise then, doesn’t cause any problems.
For people with diabetes however, it can be hard to manage this early surge in blood glucose levels. This is because their body cannot produce enough insulin or the body has become resistant to insulin, so blood sugar levels remain high.
Expert tips for identifying normal glucose rhythms
Dr Kimberly Cukier, an endocrinologist specialising in diabetes, recommends routine monitoring of blood glucose levels using a glucose meter or continuous monitor, when taking medications such as insulin or if instructed by your diabetes team.
2. Some foods can increase morning blood glucose levels
Having a healthy diet with regular mealtimes is important to keep blood glucose levels under control. Getting advice from an Accredited Practising Dietitian about which foods you can eat and the best time of the day to eat them, is an important part of your diabetes management. It is important to have this individualised to meet your needs – as everyone is different.
Expert dietary tips for avoiding high morning blood glucose levels
Robyn Perlstein, an Accredited Practising Dietitian specialising in diabetes management, recommends that if you eat snacks before bed, always include some protein along with some carbohydrates, e.g. yoghurt, milk, or cheese & biscuits. Eating breakfast (with your required insulin dose) can also help lower morning blood glucose levels as it interrupts the continued release of glucose from the liver.
3. Exercise can help lower morning blood glucose levels
Exercise helps lower blood glucose levels in two ways:
- When you exercise, the muscles in your body need energy (glucose) to work, which means they take glucose out of the blood.
- Exercise helps insulin work more effectively to lower blood glucose.
Expert tips about exercise for lowering morning blood glucose levels
Dr Kimberly Cukier recommends trying a gentle 10-minute walk after an evening meal. A morning walk can also help reduce glucose levels in the blood.
4. A good night’s sleep can help control morning blood sugar levels
Experts recommend 6-9 hours per night, as poor sleep can aggravate insulin resistance and contribute to high blood sugar levels.
If you snore or wake up feeling unrested, talk to your doctor or your diabetes management team. You may have a condition called sleep apnoea (pronounced ap-nee-yah), caused by your airway becoming partially blocked while you sleep. Sleep apnoea causes oxygen levels in the body to fall, which in turn causes some hormonal changes that lead to impaired glucose control. Sleep apnoea is a risk factor for type 2 diabetes, and type 2 diabetes is a risk factor for sleep apnoea .
Expert tips about sleep and blood glucose levels
Dr Kimberly Cukier recommends monitoring your sleep habits and discussing sleep concerns with your health care professional.
5. Drink enough water
Drinking water is important to help control blood sugar levels but can be particularly helpful first thing in the morning. This is because your body can become relatively dehydrated overnight, so the sugar in your blood becomes more concentrated. Drinking water helps rehydrate the body and balance the glucose levels in the blood.
When blood sugar levels get high, your kidneys will try to make more urine to remove the excess glucose from your system. Drinking water helps the kidneys make urine to flush out the glucose.
Alcohol also causes the kidneys to make more urine as alcohol can lead to dehydration. This is because alcohol prevents the release of a hormone that causes water to be reabsorbed by the body. This is why it is even more important to keep well hydrated (by drinking water) if you are drinking alcohol.
Expert tips about drinking to control blood glucose levels
Robyn Perlstein recommends following the Australian Guidelines on sensible drinking – drink no more than 2 standard drinks on any day and drink plenty of water /non-alcoholic beverages along with it. Always stay well hydrated, especially after waking in the morning since no water has been consumed overnight.
6. Avoid stress
While easier said than done, managing your stress is very important for your health. Stress affects your body in so many different ways, from affecting your hormones, diet, sleep patterns and exercise – all of which are important for controlling blood glucose levels.
Expert tips to control stress
Everyone is made differently, so finding a method that suits you is important. Techniques to help manage stress include talking to a friend, doctor or counsellor, relaxation techniques (like yoga, meditation, quiet walks), doing activities you enjoy and doing something active. It is good to ask for help when things get tough.
For more advice and support dealing with stress, see the Beyond Blue website or call 1300 22 4636.
For information and help managing your mental health with diabetes, see resources developed by Diabetes Australia.
If you are having trouble controlling blood glucose levels, please talk to your doctor or your diabetes management team.
They will help you figure out why your blood sugar levels are high and develop a plan specifically tailored for you. This is important, as good control of blood glucose levels can help avoid serious health problems.
For more information and support, see your GP, your endocrinologist or your diabetes management team.
For information about how glucose and insulin are regulated, see our information about the pancreas.
The Diabetes Australia website has more information and resources.
Dr Kimberly Cukier is an endocrinologist at Geelong Endocrinology and Diabetes Clinic and a senior clinical lecturer at Deakin University. She specialises in diabetes care and is actively involved in teaching medical students and training new physicians. Dr Cukier is a member of the Endocrine Society of Australia.
Robyn Perlstein is a Senior Dietitian at Geelong Endocrinology and Diabetes Clinic and is a Research Fellow at Deakin University. She has specialist interests in type 1 and type 2 diabetes and is actively involved in ensuring future doctors have a better understanding during their training about nutrition.
 Jehan S, Myers AK, Zizi F et al (2018). Obesity, obstructive sleep apnea and type 2 diabetes mellitus: Epidemiology and pathophysiologic insights. Sleep Med Disord, 2(3), 52-58.