High blood sugar, or hyperglycemia, can present with many symptoms based on its severity, states WebMD. In general, high blood sugar can cause symptoms such as increased thirst, increased urination, fatigue and blurry vision.
People who have diabetes are at risk for developing high blood sugar, states WebMD. Diabetic patients who do not control their disease very well are at the highest risk for developing high blood sugar. Mild, moderate and severe high blood sugar levels can cause a myriad of symptoms.
Mild high blood sugar occurs when a patient's blood glucose levels are consistently between 200 and 350 milligrams per deciliter of blood. These patients may experience extreme thirst, increased urination, weight loss, increased appetite and fatigue, states WebMD.
Moderate to severe high blood sugar occurs when a patient's blood glucose levels are consistnetly above 350 milligrams per deciliter of blood. The symptoms of moderate to severe high blood sugar include blurry vision, lightheadedness, flushed skin, restlessness and drowsiness, states WebMD. Patients who have moderate to severe high blood sugar levels may also experience rapid breathing, rapid heart rate, a fruity breath odor and loss of appetite. These latter symptoms occur in patients who have difficulty producing enough insulin, states WebMD.