Blood glucose that gets too high or too low can be dangerous. To stay safe and healthy, check your blood glucose regularly and watch for certain symptoms, like being very hungry, tired or sleepy. If your blood glucose is outside the normal range, take the steps described below to start feeling better. Hyperglycemia means that you have too much blood glucose. It
happens when your blood glucose level is around 200 mg/dL or higher. Hyperglycemia can happen if you miss taking your diabetes medications, eat too much or do not get enough exercise. Sometimes, the medications you take for other problems cause high blood glucose. Symptoms of hyperglycemia include: If you have these symptoms, check your blood glucose right away. If it’s too high, follow these steps: If your insulin level is too low, your blood glucose could become so high that it is unsafe. You might develop a serious problem called diabetic ketoacidosis (or DKA). This usually happens in people with Type 1 diabetes and those with glucose levels over 500. If you have DKA, chemicals called ketones start to make a lot of acid in your body. The acid and
high blood glucose can make you very sick. You might also become dehydrated (lose body fluid). You can prevent DKA by carefully giving yourself the correct insulin dose every day. If you have any of the following symptoms of DKA, get to your local emergency department right away. You need to be treated with insulin and fluids that are given to you through an IV (a thin tube placed in your arm):High Blood Glucose: Hyperglycemia
High Blood Glucose: Diabetic Ketoacidosis (DKA)
- Blurry vision
- Decreased appetite
- Dry mouth, eyes or skin
- Fast breathing
- Feeling confused or irritable
- Feeling very weak or tired
- Fruity-smelling breath
- Stomach pain, nausea or vomiting
Low Blood Glucose: Hypoglycemia
Hypoglycemia can occur when blood glucose drops below normal levels or drops too quickly. Your blood glucose level is too low if it is under 70 mg/dL.
Hypoglycemia can be caused by:
- A combination of these factors
- Being more active than usual
- Drinking alcohol
- Eating at the wrong time for the medications you take
- Skipping or not finishing meals or snacks
- Taking too much diabetes medication
You can have hypoglycemia without any symptoms. That makes it important to check your blood glucose levels regularly. When hypoglycemia does cause symptoms, they can include:
- Being sweaty
- Fast heartbeat
- Feeling irritable
- Feeling shaky
- Feeling tired
- Headache
- Hunger
If you have these symptoms, check your blood glucose right away. If it is too low (under 70 mg/dL), take something with sugar right away. This quickly raises your blood glucose level. Some good options include:
- Five to six hard candies
- One-half cup (4 oz) of fruit juice or regular soda
- Three glucose tablets
You should also check your blood glucose again after 15 minutes. If it’s still low, again take something with sugar. Check your blood glucose level again after another 15 minutes. If it is still low, call a member of your diabetes team. If your next meal is more than an hour away, eat a small snack.
*The content on this website is for informational purposes only and is not medical advice. Please consult a physician regarding your specific medical condition, diagnosis and/or treatment.
Topic Overview
High blood sugar (hyperglycemia) is most often seen in people who have diabetes that isn't well controlled. The symptoms of high blood sugar can be mild, moderate, or severe.
Mild high blood sugar
If your blood sugar levels are consistently higher than your target range (usually 11 mmol/L to 20 mmol/L, and 11 mmol/L to 14 mmol/L in children), you may have mild symptoms of high blood sugar. You may urinate more than usual if you are drinking plenty of liquids. Some people who have diabetes may not notice any symptoms when their blood sugar level is in this range. The main symptoms of high blood sugar are:
- Increased thirst.
- Increased urination.
- Weight loss.
- Fatigue.
- Increased appetite.
Young children are unable to recognize symptoms of high blood sugar. Parents need to do a home blood sugar test on their child whenever they suspect high blood sugar.
If you don't drink enough liquids to replace the fluids lost from high blood sugar levels, you can become dehydrated. Young children can become dehydrated very quickly. Symptoms of dehydration include:
- A dry mouth and increased thirst.
- Warm, dry skin.
Moderate to severe high blood sugar
If your blood sugar levels are consistently high (usually above 20 mmol/L in adults and above 14 mmol/L in children), you may have moderate to severe symptoms of high blood sugar. These symptoms include:
- Blurred vision.
- Extreme thirst.
- Light-headedness.
- Flushed, hot, dry skin.
- Restlessness, drowsiness, or difficulty waking up.
If your body produces little or no insulin (people with type 1 diabetes and some people with type 2 diabetes), you also may have:
- Rapid, deep breathing.
- A fast heart rate and a weak pulse.
- A strong, fruity breath odour.
- Loss of appetite, belly pain, and/or vomiting.
If your blood sugar levels continue to rise, you may become confused and lethargic. You also may become unconscious if your blood sugar levels are very high.
Credits
Current as of: July 28, 2021
Author: Healthwise Staff
Medical Review:
E. Gregory
Thompson MD - Internal Medicine
Donald Sproule MDCM, CCFP - Family Medicine
Adam Husney MD - Family Medicine
Kathleen Romito MD - Family Medicine
Rhonda O'Brien MS, RD, CDE - Certified Diabetes Educator