For both men and women, a normal blood glucose level after fasting for at least eight hours is between 70 and 99 milligrams per deciliter, according to Virginia Mason Medical Center. A normal blood sugar reading two hours after eating is less than 140 milligrams per deciliter.
Blood glucose levels change throughout the day and are dependent on diet and activity level. In patients with diabetes, blood glucose levels are abnormally high, which can lead to symptoms such as fatigue, increased thirst, increased urination or unintentional weight loss. However, many patients with diabetes are asymptomatic, and the diagnosis comes as a surprise, notes Virginia Mason Medical Center.