What Can Happen to My Body if My Sugar Is Higher Than 600 for Many Hours?

Blood sugar more than 600 can cause a coma.
Image Credit: Phynart Studio/E+/GettyImages

Dangerously high blood sugar levels cause ketoacidosis. A blood sugar level over 600 for many hours is considered extremely dangerous and should be treated at a hospital. Hyperglycemia is the medical term for elevated blood sugar levels.


According to the American Diabetes Association, blood sugars more than 240 can cause ketoacidosis — a condition where the body starts using fat for energy. Ketoacidosis can lead to coma and death.

Video of the Day

Ketones And High Blood Sugar

When blood sugar levels are high for prolonged periods of time and the body starts using fat for energy, toxic ketones are produced. The presence of ketones can be measured in the urine. They are the acid byproduct of fat breakdown.


Diabetes is the most common cause of high blood sugar levels. Hyperglycemia can also be caused by acute pancreatitis. Early symptoms include frequent urination that leads to dehydration and excessive thirst. Blood sugar more than 600 for many hours could then lead to difficulty breathing, weakness, confusion and decreased level of consciousness.


Blood sugar levels become dangerously high when the body does not have enough insulin, which is produced in the pancreas. When ketones develop in the body, the liver produces more glucose to correct the problem, but without insulin, blood sugar levels continue to rise.


For patients diagnosed with diabetes, ketoacidosis can develop from missed insulin doses, not enough insulin, infection, trauma or other acute illness.


Prolonged high blood sugar levels can cause swelling in the brain — cerebral edema. Children are more susceptible, but adult cases have been documented, according to Elliot J. Crane, MD, Departments of Pediatrics and Anesthesiology, Stanford University Medical Center. Other complications include organ damage from low blood pressure, heart attack and kidney failure.



Prompt treatment of an high extremely high blood sugar level is paramount to prevent complications. Insulin and intravenous fluids are necessary to normalize glucose levels. Medications to control vomiting and respiratory support with oxygen or ventilator support might be necessary to correct acidosis.

The underlying cause of high blood sugar must also be addressed. Glucose levels of 600 for extended periods are likely to cause other imbalances. Sodium, potassium, carbon dioxide and chloride levels should be closely monitored and replaced as needed.




Report an Issue

screenshot of the current page

Screenshot loading...