Blood glucose or blood sugar is the primary energy source of your bodyâ€™s cells. At normal levels, sugar in the blood is 4-6 mmol/Liter or 70-100 mg/dL. It is at its lowest before you eat in the morning and at its highest when you eat. When a person fails to maintain normal levels of blood sugar, either hyperglycemia or hypoglycemia sets in. This is a condition that is known as Diabetes mellitus. Diabetics need to lower blood sugar fast when it rises all of a sudden. It can be really hard for them to continue what they are doing and feel well the rest of the day. If ever they live alone or happen to be in a place without anyone else, it would be very hard for them to seek immediate medical assistance.