For people with diabetes, keeping blood sugar levels within a target range is key to avoiding serious complications down the road, like kidney disease, nerve damage and vision problems. Proper diet, regular exercise and medication can help keep glucose (the sugar in your blood) at a healthy level. But sometimes, even if you are following your treatment plan, your blood sugar may get high. If it does, the sooner you recognize and treat it, the less likely it is to cause long-lasting or severe health issues.
High blood sugar, also called hyperglycemia, can occur when insulin doesn’t work properly to shuttle glucose from the bloodstream into cells for use as energy, explains O’Neill. This happens when you miss a dose of insulin or when your body doesn’t produce enough insulin (type 1 diabetes).
When the body can’t use glucose for energy, it starts to break down fat and muscle for fuel, producing chemicals known as ketones. These pass out of the body in urine, causing you to pee more frequently and become dehydrated. High blood sugar can also make you feel tired, despite eating more food than usual.
People with diabetes can prevent or treat high blood sugar with the help of a doctor or registered dietitian. The American Diabetes Association recommends keeping blood sugar below 80 to 130 milligrams per deciliter (mg/dL) before a meal and below 180 mg/dL two hours after eating. The ADA also recommends getting an A1C test at least twice a year if you have diabetes, and testing your blood glucose often—especially before and after exercising.
It’s important to know what causes your blood sugar to be high so that you can avoid it or treat it right away, says O’Neill. This may include consuming a small snack to help raise the blood sugar, such as a piece of fruit or a gummy candy, and incorporating more activity into your daily routine to increase the flow of glucose from the bloodstream into cells.
Other reasons for high blood sugar may include taking certain medications, such as steroids, beta blockers or birth control pills; or increased stress levels. Other health conditions, such as kidney or liver problems, can also raise your blood sugar, as can some medical procedures, such as surgery or a dental procedure.
You may also experience high blood sugar if you have a condition called hypoglycemia unawareness, which means your symptoms don’t always alert you to low blood sugar. For example, if you have had low blood sugar for years, you may no longer notice the early warning signs of it, such as thirst or hunger. In this case, your doctor will likely recommend a glucometer and suggest you follow the ADA’s “15-15 Rule,” which advises that you consume 15 grams of carbohydrates, wait 15 minutes and check your glucose again. You should also drink more water to replace the fluids you lose through urination.