Signs of High Blood Sugar (Hyperglycemia)
Written by John Ngijseh
An important part of managing diabetes is recognising when your blood glucose (sugar) becomes too high and knowing what to do about it. In this article we will talk about what is too high a blood glucose level, how this can happen, help you recognise the key symptoms of high blood glucose and give some advice on what action you can take if it happens.
So what is too high a blood glucose?
When blood glucose is higher then 180 mg/dl (in US units) or 10mmol/L (in UK units) measured two hours after food, then the blood glucose is too high. The technical term for this is hyperglycemia.
How is Hyperglycemia caused?
Hyperglycemia is often a result of when food, activity and medications are not balanced. Some of the common reasons why this balance can be altered are: nn· Too much food or the wrong type foodn· Not enough medicationn· Not enough insulinn· Poor injection techniquen· Overuse of injection sitesn· Infections or illnessn· Stressn· Increase in weight
A common cause of hyperglycemia in diabetics is missing dose of insulin or not taking enough. This also the case with diabetic oral medication. Eating too much, can also cause a rise in blood sugar levels
Signs and Symptoms of hyperglycemia
In the early stages, there are likely to be no symptoms at all and even when symptoms do arise they may come on so slowly that they are not noticed.
You may get some of following symptoms: nn· More hunger or thirst then usualn· Excessive urinationn· Tiredness and lethargyn· Frequent infectionsn· Blurred visio
If untreated, high blood glucose may result in diabetic ketoacidosis. Diabetic ketoacidosis is a serious condition due to a lack of insulin. This causes the body to try to find energy from other sources as it cannot use the glucose in the blood. Ketones and acid form as a result.
The condition is characterised by vomiting, drowsiness, smell of acetone (like pear drops) on the breath and can result in coma.
Monitoring your blood glucose regularly may help you identify when your blood glucose has become too high and recognising the warning signs will help highlight to you that action needs to be taken.
What to do if you experience Hyperglycemia
Hyperglycemia can usually be treated with either oral diabetic medications or insulin. If blood glucose levels don’t respond to insulin or medication, diabetics are advised to contact their GP immediately.
Remember: nn· Consult your doctorn· Continue with your diabetes treatmentn· Consume plenty of fluidsn· Test your blood glucose levels every 2-4 hrsn· Adjust your meal plann· Adjust your medication or insulin (only if instructed by doctor to do so)
As with many things in life, prevention is better then cure. Be aware of the causes of hyperglycemia and do what you can to prevent them.
Article author
About the Author
Further reading
Further Reading
Article
Fear of Being Healthy?
Why do some people have trouble addressing health concerns?
October 8, 2026
Article
Why General Practice Accreditation Delivers Real Value Beyond Compliance
General practice accreditation is more than a compliance requirement. This article explains how accreditation supports patient safety, quality improvement, practice governance, funding eligibility, and ongoing trust in Australia’s healthcare system.
October 8, 2026
Website
HealthNexo
HealthNexo provides trustworthy, evidence-based health information and the latest health news. We cover disease prevention, diagnosis, nutrition, fitness, and wellness to help you make informed decisions for a healthier life.
October 2, 2026
Article
Dengue Diagnosis: Which Blood Tests Are Used and When?
Dengue diagnosis blood tests include RT-PCR/NAAT, NS1, IgM, IgG, and CBC. Early tests detect the virus, while IgM becomes more useful later. CBC helps monitor the patient but cannot confirm dengue alone.
October 2, 2026