If you are a diabetic (or show signs that indicate you might be), it is especially important to monitor your blood sugar levels regularly. In non-diabetics, the normal blood sugar range is anywhere from 70 to 130 mg/dl. After a meal, blood sugar levels rise and will generally peak at an average of 180 mg/dl one to two hours after the start of the meal.
In people with diabetes, however, blood sugar levels may be higher than 130 mg/dl even when they haven't eaten all day - or it might remain constantly on the high end of around 180 mg/dl or higher.
If your blood sugar is too high (known as hyperglycemia) you may notice symptoms such as excessive thirst; frequent urination; constant hunger; dry skin; skin infections that seem as if they are never healing; even minor wounds are strangely slow to heal; fatigue or drowsiness; blurry vision; and nausea.
Sometimes taking certain medications, being under heavy stress, illness or infection can also make your blood sugar levels unusually high. If you regularly show signs of high blood sugar, talk to your doctor - you might need a change in diet or medication.
Untreated high blood sugar can lead to ketoacidosis, a life-threatening condition. The symptoms of ketoacidosis include shortness of breath; "fruity" breath; "cotton mouth" (extremely dry mouth); persistent nausea/throwing up. If you have these symptoms, do not exercise (even if you normally do), but instead go to the doctor or the emergency room immediately. In the longer-term, lifestyle changes in the form of dietary changes, regular exercise, and monitoring of blood glucose, are all needed in order to bring blood sugar back into normal or near-normal ranges.