My blood sugar is consistently 240mg after 8hr fast but my physician tested and said im not diabetic. my father is diabetic and said my blood sugar should not be that high after fasting. how could my blood sugar not fall if im not diabetic?

Your diet will greatly impact your fasting blood sugar. What was your carbohydrate and sugar intake in the preceding 24 hours? Are you sedentary or do you exercise every day? What is your A1C reading? So much more info is needed to advise you further. In any event, watch your diet and eat healthy.

Two or more blood sugars above 200 is a way to diagnose diabetes. If your hemoglobin A1C is in the normal range, it is possible you can diet control your blood sugars. Seeing a nutritionist to instruct you on the proper diet to control your blood sugars would be an important next step-your doctor can make this referral. Exercise would also help in your blood sugar control. Good luck to you!

You need to consult an endocrinologist. If your fasting plasma glucose level has been above 126 mg, twice, you are diabetic and need to seek treatment. Visit this site for information: https://www.diabetes.org/a1c/diagnosis