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How the Blood Sugar of Diabetes Affects the Body

Diabetes mellitus leads to persistently elevated blood sugar levels. Over time, high sugar levels damage the body and can lead to the multiple health problems associated with diabetes.

But why are high blood sugars so bad for you? How much sugar in the blood is too much? And what are good sugar levels, anyway? WebMD takes a look at how your sugar level affects diabetes and your health.

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Diabetes and Normal Blood Sugar Levels

At present, the diagnosis of diabetes or prediabetes is based in an arbitrary cut-off point for a normal blood sugar level. A normal sugar level is currently considered to be less than 100 mg/dL when fasting and less than 140 mg/dL two hours after eating. But in most healthy people, sugar levels are even lower.

During the day, blood glucose levels tend to be at their lowest just before meals. For most people without diabetes, blood sugar levels before meals hover around 70 to 80 mg/dL. In some, 60 is normal; in others, 90. Again, anything less than 100 mg/dL while fasting is considered normal by today's standards.

What's a low sugar level? It varies widely, too. Many people's sugar levels won't ever fall below 60 mg/dL, even with prolonged fasting. When you diet or fast, the liver keeps sugar levels normal by turning fat and muscle into sugar. A few people's sugar levels may fall somewhat lower. Without taking diabetes medicine, though, or having uncommon medical problems, it's difficult to drop sugar levels to an unsafe point.

Sugar Levels, Diabetes, and Prediabetes

Sugar levels higher than normal mean either diabetes or pre-diabetes is present.

There are several ways diabetes is diagnosed:

  • The first is known as a fasting plasma glucose test. A person is said to have diabetes if his or her fasting blood sugar level is higher than 126 mg/dL after not eating -- fasting -- for eight hours.
  • The second method is with an oral glucose tolerance test. After fasting for eight hours, a person is given a special sugary drink. That person is said to have diabetes if two hours after the drink he or she has a sugar level higher than 200.
  • The third way is with a randomly checked blood sugar level. If it is greater than 200, with symptoms of increased urination, thirst, and/or weight loss, that person is said to have diabetes. A fasting sugar level or oral glucose tolerance test will be needed to confirm the diagnosis.

But diabetes is not like a switch that gets turned on and off -- healthy one day, diabetic the next. Any sugar levels higher than normal are unhealthy. A blood sugar higher than normal, but not meeting the above criteria for full-blown diabetes, is called prediabetes.

According to the American Diabetes Association, 79 million people in the U.S. have prediabetes. People with prediabetes are five to six times more likely to develop diabetes over time. Prediabetes also increases the risk for cardiovascular disease, although not as much as diabetes does. It's possible to prevent the progression of prediabetes to diabetes, with diet and exercise.

WebMD Medical Reference

Is This Normal? Get the Facts Fast!

Check Your Blood Sugar Level Now
What type of diabetes do you have?
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Answer:
Low
0-69
Normal
70-130
High
131+

Your level is currently

If the level is below 70 and you are experiencing symptoms such as shaking, sweating or difficulty thinking, you will need to raise the number immediately. A quick solution is to eat a few pieces of hard candy or 1 tablespoon of sugar or honey. Recheck your numbers again in 15 minutes to see if the number has gone up. If not, repeat the steps above or call your doctor.

People who experience hypoglycemia several times in a week should call their health care provider. It's important to monitor your levels each day so you can make sure your numbers are within the range. If you are pregnant always consult with your health care provider.

Congratulations on taking steps to manage your health.

However, it's important to continue to track your numbers so that you can make lifestyle changes if needed. If you are pregnant always consult with your physician.

Your level is high if this reading was taken before eating. Aim for 70-130 before meals and less than 180 two hours after meals.

Even if your number is high, it's not too late for you to take control of your health and lower your blood sugar.

One of the first steps is to monitor your levels each day. If you are pregnant always consult with your physician.

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