Hyperglycaemia (high blood sugar)
Hyperglycaemia (high blood sugar)
Overview
Hyperglycaemia (high blood sugar) can affect people with type 1 diabetes and type 2 diabetes, as well as pregnant women with gestational diabetes.
It can occasionally affect people who don’t have diabetes, but usually only people who are seriously ill, such as those who have recently had a stroke or heart attack, or have a severe infection.
Hyperglycaemia shouldn’t be confused with hypoglycaemia, which is when a person’s blood sugar level drops too low.
This information focuses on hyperglycaemia in people with diabetes.
Is hyperglycaemia serious?
The aim of diabetes treatment is to keep blood sugar levels as near to normal as possible. But if you have diabetes, no matter how careful you are, you’re likely to experience hyperglycaemia at some point.
It’s important to be able to recognise and treat hyperglycaemia, as it can lead to serious health problems if left untreated.
Occasional mild episodes aren’t usually a cause for concern and can be treated quite easily or may return to normal on their own. However, hyperglycaemia can be potentially dangerous if blood sugar levels become very high or stay high for long periods.
Very high blood sugar levels can cause life-threatening complications, such as:
- diabetic ketoacidosis (DKA) – a condition caused by the body needing to break down fat as a source of energy, which can lead to a diabetic coma; this tends to affect people with type 1 diabetes
- hyperosmolar hyperglycaemic state (HHS) – severe dehydration caused by the body trying to get rid of excess sugar; this tends to affect people with type 2 diabetes
Regularly having high blood sugar levels for long periods of time (over months or years) can result in permanent damage to parts of the body such as the eyes, nerves, kidneys and blood vessels.
If you experience hyperglycaemia regularly, speak to your doctor or diabetes care team. You may need to change your treatment or lifestyle to keep your blood sugar levels within a healthy range.
Common Symptoms
⚠️ This symptom list is for educational purposes. Having these symptoms does not mean you have this condition. See a doctor for proper diagnosis.
Medicines Commonly Used
⚠️ These medicines are commonly used for confirmed diagnoses of this condition. This is NOT a recommendation or prescription. Treatment must be determined by your doctor.
No medicines have been linked to this condition yet.
When to See a Doctor
Contact your diabetes care team right away if your blood sugar is high and you also notice:
- feeling sick or actually vomiting
- pain in your abdomen (tummy)
- fast, deep breathing
- signs of dehydration, such as a headache, dry skin, and a weak, rapid heartbeat
- trouble staying awake
These symptoms could point to diabetic ketoacidosis or a hyperosmolar hyperglycaemic state (explained above), and you may need to be treated in hospital.
Causes
What causes high blood sugar?
Many things can push blood sugar levels up in people who have diabetes, including:
- feeling stressed
- being unwell, even with something as ordinary as a cold
- eating more than usual, such as snacking between meals
- not getting enough exercise
- dehydration
- missing a dose of your diabetes medicine, or taking the wrong dose
- treating a low blood sugar episode (hypoglycaemia) with more sugar than actually needed
- taking certain medicines, such as steroids
Sometimes children and young people also have occasional episodes of high blood sugar during growth spurts.
Treatment
If you have been diagnosed with diabetes and you notice symptoms of high blood sugar, follow the advice your care team has already given you to bring your levels down. If you are not sure what to do, contact your GP or care team for guidance.
You may be advised to:
- change your diet, for example by cutting back on foods that push your blood sugar up, such as cakes or sugary drinks
- drink plenty of sugar free fluids, which can help if you are dehydrated
- move more often, since gentle, regular activity like walking can lower your blood sugar, especially if it helps you lose weight
- adjust your insulin dose if you use insulin, following the specific advice your care team gives you
You may also be told to check your blood sugar more closely, or to test your blood or urine for substances called ketones, which are linked to diabetic ketoacidosis.
Until your blood sugar is back under control, stay alert for any additional symptoms that could point to a more serious condition, as described below.
Prevention
There are simple ways to lower your risk of severe or long-lasting hyperglycaemia:
- Be careful what you eat. Pay attention to how snacking and eating sugary foods or carbohydrates can affect your blood sugar level.
- Stick to your treatment plan. Take your insulin or other diabetes medications as recommended by your care team.
- Stay as active as possible. Regular exercise can help stop your blood sugar level from rising, but check with your doctor first if you're taking diabetes medication, since some medicines can lead to hypoglycaemia if you exercise too much.
- Take extra care when you're ill. Your care team can give you some sick day rules that outline what you can do to keep your blood sugar level under control during an illness.
- Monitor your blood sugar level. Your care team may suggest using a device to check your level at home, so you can spot a rise early and take steps to stop it.