When you have diabetes, your blood sugar (aka blood glucose) levels may be consistently high. Over time, this can damage your body and lead to many other problems. How much sugar in the blood is too much? And why is high glucose so bad for you? Here’s a look at how your levels affect your health. They're less than 100 mg/dL after not eating (fasting)
for at least 8 hours. And they're less than 140 mg/dL 2 hours after eating. During the day, 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. For some people, 60 is normal; for others, 90. What's a low sugar level? It varies widely, too. Many people's glucose won't ever fall below 60, even with prolonged fasting. When you diet or fast, the liver keeps your levels normal by turning fat
and muscle into sugar. A few people's levels may fall somewhat lower. Doctors use these tests to find out if you have diabetes: Any sugar levels higher than normal are unhealthy. Levels that are higher than normal, but not reaching the point of full-blown diabetes, are called prediabetes. According to the
American Diabetes Association, 86 million people in the U.S. have this condition, which can lead to diabetes if you don't make healthy lifestyle changes that your doctor recommends. It also raises the risk for heart disease, although not as much as diabetes does. It's possible to keep prediabetes from becoming diabetes with diet and exercise. High Blood Sugar, Diabetes, and Your Body
What Are Normal Blood Sugar Levels?
Diagnosis
Sugar and Your Body
Why are high blood sugar levels bad for you? Glucose is precious fuel for all the cells in your body when it's present at normal levels. But it can behave like a slow-acting poison.
- High sugar levels slowly erode the ability of cells in your pancreas to make insulin. The organ overcompensates and insulin levels stay too high. Over time, the pancreas is permanently damaged.
- High levels of blood sugar can cause changes that lead to a hardening of the blood vessels, what doctors call atherosclerosis.
Almost any part of your body can be harmed by too much sugar. Damaged blood vessels cause problems such as:
- Kidney disease or kidney failure, requiring dialysis
- Strokes
- Heart attacks
- Vision loss or blindness
- Weakened immune system, with a greater risk of infections
- Erectile dysfunction
- Nerve damage, also called neuropathy, that causes tingling, pain, or less sensation in your feet, legs, and hands
- Poor circulation to the legs and feet
- Slow wound-healing and the potential for amputation in rare cases
Keep your blood sugar levels close to normal to avoid many of these complications. The American Diabetes Association's goals for blood sugar control in people with diabetes are 70 to 130 mg/dL before meals, and less than 180 mg/dL after meals.
Fasting, as the name suggests, means refraining from eating of drinking any liquids other than water for eight hours. It is used as a test for diabetes.
v After fasting, a carbohydrate metabolism test is conducted which measures blood glucose levels.
Glucagon during fasting
When fasting the hormone glucagon is stimulated and this increases plasma glucose levels in the body.
If a patient doesn’t have diabetes, their body will produce insulin to rebalance the increased glucose levels.
However people with diabetes either don’t produce enough insulin to rebalance their blood sugar (typically in type 1 diabetes ) or their body is not able to use the insulin effectively enough (typical of type 2 diabetes).
Consequently when blood glucose levels are tested, people with diabetes will have blood sugar levels significantly higher than people who do not have diabetes.
What is the fasting blood sugar test used for?
The fasting blood sugar test is also used to test the effectiveness of different medication or dietary changes on people already diagnosed as diabetic
Fasting tests
The fasting test should be conducted on two separate occasions to ensure consistent results and in order to avoid a false diagnosis.
This is the case as increased blood glucose levels may be as a result of Cushing’s syndrome liver or kidney disease, eclampsia and pancreatitis.
However many of these conditions are often picked up in lab diagnostic tests.
Fasting test results
The results of a fasting test with respect to glucose levels in the body are as follows:
- Normal: 3.9 to 5.4 mmols/l (70 to 99 mg/dl)
- Prediabetes or Impaired Glucose Tolerance: 5.5 to 6.9 mmol/l (100 to 125 mg/dl)
- Diagnosis of diabetes: 7.0 mmol/l (126 mg/dl) or above [361]
The American Diabetes Association reduced the level of diagnosis in this test from 140 to 126 mg/dl in 1997.