It could be yes. High glucose has a number of symptoms and tiredness, along with blurred vision is one. However i'd recommend visiting your doctor again for further testing to rule out anything else!
Yes it does.
The most common cause of elevated serum glucose levels is recent food intake. The next possibility is diabetes mellitus.
Wikipedia has a good overall summery of what glucose levels are and how glucose works around your body. If you're looking for a simpler definition NHS choices explains why, how and what may cause high blood glucose levels and how it may be treated.
Eating candy can cause a person's glucose to go up especially if the person has diabetes. If one has diabetes, glucose levels are affected by foods high in carbohydrates.
One medication that i know that makes levels go high is Prednisone, it gave me diabetes.
Pre Diabetes is when you blood glucose levels are higher than normal but they aren't high enough to cause diabetes. You have to diet and exercise to fix your blood glucose levels.
Insuline and Glucagon control blood glucose. Insuline: brings down high levels of glucose. Glucagon: brings glucose levels back to normal, (brings glucose levels up).
high levels of ketone and glucose can cause loss of consciousness in dka
Excessive diuresis withou high blood glucose levels
Your glucose levels should be between 70 to 130 milligrams (mg/dL). As far as I know the "normal" range does not change as you age, although it is different for children. Your diet sounds good which is usually the cause for high glucose levels, but there are self testing kits available should you wish to keep an eye on them levels.
There are many reasons for high glucose levels. It usually indicates diabetes and can be caused by obesity, high alcohol consumption, lack of exercise and also stress.
Well, a healthy level of blood glucose wouldn't be too high or too low. Instead, it would be in the middle between high and low. Unhealthy levels of blood glucose would be an extremely high number.