Humans need a certain amount of sugar in their blood to function properly. Blood sugar, known more precisely as glucose, energizes the brain, which in turn controls almost every aspect of human activity. Unlike muscles that can derive energy from the fat you consume, the brain requires glucose to power its operations. Therefore, keeping blood glucose at optimal levels is the best way to ensure that your brain has all the energy it needs.
A healthy blood glucose level varies significantly throughout the day, according to William C. Shiel Jr., an editor at MedicineNet.com. The normal range for someone who has just awoken and not yet eaten breakfast would be between 80 mg/dl (milligrams per deciliter) and 120 mg/dl, and a similar range would be normal before each meal of the day. A normal reading two hours after a meal would be near 160 mg/dl or below, while the normal range at bedtime should be between 100 and 140 mg/dl, according to Shiel.
Blood glucose levels that fall significantly outside the ranges defined by Shiel are abnormal and signal to your doctor that something is amiss. Too much blood glucose constitutes a condition known as hyperglycemia, and it is particularly dangerous for those who have diabetes. Abnormally low levels of blood glucose constitute hypoglycemia, which is also a condition that diabetics must take great care to avoid.
Diabetics must closely monitor their blood glucose level to avoid the symptoms of hyperglycemia, which can lead to diabetic coma, or ketoacidosis, if allowed to go unchecked. Symptoms of hyperglycemia in diabetics may include increased urination and extreme thirstiness. For patients with type 1 diabetes, this may be a sign that they failed to take enough insulin, while for those with type 2 diabetes it could mean that insulin levels are near normal but not being as effective as they should be, according to the American Diabetes Association. Exercise can help bring diabetics' blood sugar levels down to acceptable levels but should not be attempted if their blood glucose level is 240 mg/dl or above and ketones are present in their urine. If these conditions are present, immediate medical care should be sought.
The symptoms of low blood glucose levels include anxiety, confusion, dizziness, difficulty speaking, hunger, nervousness, shakiness, sleepiness, excessive perspiration and weakness, according to the National Diabetes Information Clearinghouse. Diabetics whose blood glucose readings are below 70 mg/dl should promptly take one of the following to adjust blood sugar levels higher: 1 tbsp. of honey or sugar, three or four glucose tablets, 4 oz. of any fruit juice or non-diet soda, 8 oz. of milk, or five or six pieces of hard candy.
Tips for Nondiabetics
Nondiabetics are far less likely to suffer from hyperglycemia because the self-regulatory mechanisms of their bodies ordinarily do a very good job of keeping blood glucose levels below the danger point. However, in the rare event that a nondiabetic is suffering from hyperglycemia, the symptoms---frequent urination and thirstiness---would be the same. In the same way, hypoglycemia is relatively rare among nondiabetics but would produce similar symptoms if blood glucose levels were abnormally low. A nondiabetic experiencing either of these conditions should consult a doctor promptly.