How to Handle High Blood Sugar

People without diabetes have normal glucose levels less than 140 mg/dL two hours after eating and less than 100 mg/dL when fasting (measured in the morning when you haven’t eaten for at least eight hours). Glucose levels (also known as blood sugar levels) that are consistently above these numbers can cause serious damage to virtually every part of your body in the long term. Complications of prolonged high blood sugar—called hyperglycemia— include heart disease, stroke, eye disease, kidney disease and nerve disease [LINK: article on complications of diabetes].

The most common cause of elevated blood glucose levels is diabetes mellitus, a disease that occurs when the body’s ability to regulate glucose is altered because the pancreas doesn’t produce either enough or any insulin to shuttle glucose into the cells for energy. Generally, high blood glucose is broken down into two categories:

  • Fasting hyperglycemia is defined as a blood glucose level above 130 mg/dL in people with diabetes who haven’t eaten for at least 8 hours.
  • Postprandial or reactive hyperglycemia is defined as a blood glucose level of 180 mg/dL in people with diabetes one to two hours after eating.

High blood glucose is generally caused by eating too much carbohydrate-containing foods, such as potatoes, rice, bread, pasta, chips, pretzels, fruit, or sweets, as well as drinking sugary beverages such as soda, fruit juice, and sweetened iced teas and lemonade.  It can also be caused by a lack of physical activity (which naturally lowers blood sugar). Additional causes include inadequate or skipped medication, spoiled insulin or a broken glucose meter that provides inaccurate readings. Gestational diabetes, diabetes that occurs during pregnancy, is also characterized by high blood sugar.

But diabetes isn’t the only cause of high blood sugar. Medications, such as beta-blockers and steroids, as well as illnesses, such as bulimia nervosa (an eating disorder characterized by binging and purging), can change how the body regulates blood sugar. Stress, infection, injury or surgery can also affect blood sugar.

The symptoms of high blood sugar include increased thirst, frequent urination, blurry vision, dry mouth and skin, and fatigue. Additional symptoms may include poor or slow wound healing, frequent infections, extreme hunger and unexplained or unintentional weight loss.

The easiest way to prevent hyperglycemia is to control your diabetes. In addition, the following steps may help you to lower high blood sugar levels:

  • Drink enough water. Aim for at least eight 8-ounce glasses per day.
  • Do regular and consistent physical activity. Exercise helps keep blood sugar levels in check.
  • Take note of any particular circumstances around high blood glucose readings to see if you can identify a pattern.
  • Do not skip or miss doses of medication or insulin and ensure that insulin is fresh and still potent.
  • Work with your physician or endocrinologist to adjust medication dosages, if necessary.
  • Work with your registered dietitian or certified diabetes educator to adjust the amount of carbohydrates you consume during meals and snacks.

Severe high blood sugar in people with type 1 diabetes can cause a serious condition called ketoacidosis, which occurs when compounds called ketones build up in the blood. Symptoms of ketoacidosis include a high level of ketones in the urine (which can be tested at your doctor’s office or using a kit purchased at the drug store), shortness of breath, dry mouth, stomach pain, nausea, vomiting and confusion. If you think you are experiencing ketoacidosis, you need to seek medical assistance immediately.

Learn about how alcohol can affect blood sugar levels and these 9 foods that can help manage diabetes.