High blood sugar occurs when:
- Your body makes too little insulin.
- Your body does not respond to the signal insulin is sending.
High blood sugar almost always happens in people who have diabetes.
High blood sugar is also called high blood glucose, or hyperglycemia.
Insulin is a hormone that helps the body move glucose (sugar) from the blood into muscle or fat, where it is stored for later when energy is needed.
Symptoms of High Blood Sugar
Symptoms of high blood sugar can include:
- Being very thirsty or having a dry mouth
- Having blurry vision
- Having dry skin
- Feeling weak or tired
- Needing to urinate a lot, or needing to get up more often than usual at night to urinate
You may have other, more serious symptoms if your blood sugar becomes very high or remains high for a long time.
What to Think about When Your Blood Sugar Is High
High blood sugar can harm you. If your blood sugar is high, you need to know how to bring it down. Here are some questions to ask yourself if your blood sugar is high:
- Are you eating correctly?
- Are you eating too much?
- Have you been following your diabetes meal plan?
- Did you have a meal or a snack with a lot of carbohydrates, starches, or simple sugars?
Are you taking your diabetes medicines correctly?
- Has your doctor changed your medicines?
- If you take insulin, have you been taking the correct dose?
- Are you afraid of having low blood sugar? Is that causing you to eat too much or take too little insulin or other diabetes medicine?
- Have you injected insulin into a scar or overused area? Have you been rotating sites?
What else has changed?
- Have you been less active than usual?
- Do you have a cold, the flu, or another illness?
- Have you had some stress?
- Have you been checking your blood sugar ?
- Have you gained weight?
- Have you started taking any new medicines such as blood pressure drugs?
Preventing High Blood Sugar
To prevent high blood sugar, you will need to:
- Follow your meal plan
- Stay physically active
- Take your diabetes medicines as instructed
You and your doctor will:
- Set a target goal for your blood sugar levels for different times during the day. This helps you manage your blood sugar.
- Decide how often you need to check your blood sugar at home.
If your blood sugar is higher than your goals for 3 days and you do not know why, check your urine for ketones. Then call your health care provider.
Hyperglycemia - self-care; High blood glucose - self-care
American Diabetes Association. Standards of medical care in diabetes -- 2014. Diabetes Care. 2014;37 Suppl 1:S14-S80. PMID: 24357209 www.ncbi.nlm.nih.gov/pubmed/24357209.
Buse JB, Polonsky KS, Burant C. Type 2 diabetes mellitus. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 12th ed. Philadelphia, PA: Elsevier Saunders; 2011;chap 31.
Eisenbarth GS, Buse JB. Type 1 diabetes mellitus. In: Kronenberg HM, Melmed S, Polonsky KS, Larsen PR. Williams Textbook of Endocrinology. 12th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 32.
Update Date 10/25/2014
Updated by: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.