More often than not, most individuals do not even know they have high blood sugar. This is because high blood sugar usually doesn’t have any symptoms unless it is severe. In serious cases, you may experience nausea, shortness of breath, rapid heartbeat, and dizziness. If you are experiencing any of these symptoms, it’s best to contact your doctor for further recommendations. Other ways you can keep an eye on your blood sugar include using a blood sugar monitor at home or getting check-ups regularly with a physician.