Hyperglycemia, or high blood sugar, occurs when insulin levels are too low or the body is not able to properly utilize glucose for fuel, according to MedicineNet. There are many compounds and substances that alter glucose levels, such as carbohydrate-rich foods, sugar-laden beverages and caffeine.
There are two types of hyperglycemia that occur in diabetics, according WebMD. The first is fasting hyperglycemia, which is a result of not eating for eight hours or longer. The other is postprandial hyperglycemia, which is commonly caused by eating large meals. Those with frequent spikes in postprandial blood sugar have a higher risk of developing Type 2 diabetes.
Common causes for hyperglycemia in diabetics include high carbohydrate intake, increased stress levels, illness, decreased or unusually strenuous activity, and forgetting to take insulin, reports WebMD. Fatigue, increased thirst, headaches, weight loss and frequent urination are early signs of hyperglycemia. Over time, additional symptoms may occur such as decreased vision, intestinal problems, kidney damage, and slow-healing cuts and sores.
Diabetics should be aware of substances that alter blood glucose levels and adjust their intake as appropriate, states MedicineNet. Sugar-free foods have a tendency to create a spike in blood sugar due to being high in starchy carbohydrates and fat. Additionally, some cold treatments, water pills, steroids and birth control pills may cause a spike in blood glucose.