Blood sugar, or glucose, is the main type of sugar in the body. It comes from carbohydrates found in foods. Glucose is essential for providing energy to cells throughout the body, including brain cells.
Your blood sugar fluctuates throughout the day as you eat, exercise, and sleep. Stress and hormones also play a role. People with diabetes should monitor their blood sugar levels closely to make sure they stay within the appropriate target range, often determined by a doctor.
A blood sugar level outside the target range can have profound health implications. “When blood sugar levels are too high or too low, it can have serious health consequences, such as nerve damage, kidney damage and heart disease,” says Brenda Peralta, registered dietitian and certified diabetes educator at FeastGood .com.
High blood sugar (hyperglycemia) can lead to conditions like diabetes, cardiovascular disease and stroke, she explains. Low blood sugar (hypoglycemia) can cause confusion, anxiety, weakness, sweating and vision problems. Extremely low blood sugar levels can lead to seizures and fainting.
Why is blood sugar important for diabetes?
Diabetes is a condition that makes it difficult or impossible for the body to regulate glucose levels on its own. When someone lives with diabetes, their body is unable to make enough insulin or make enough insulin available for use. Insulin is a hormone that helps the body use glucose for energy. When insulin levels are too low, glucose builds up in the bloodstream and can damage organs and other tissue.
“Diabetes occurs when a person’s body is unable to adequately handle the sugar that is normally ingested in our daily diet,” says Jennifer Meller, MD, chief medical officer of Sweetch, a digital health innovation company with based in Tel Aviv, Israel. “Chronically elevated sugar levels can lead to changes in both large and small blood vessels.”
Over time, changes to the large vessels can lead to an increased risk of heart attack and stroke, while damage to the small vessels can lead to nerve damage, vision loss and kidney failure, explains Dr. Meller.
For people living with diabetes, maintaining healthy blood sugar levels is essential to prevent serious health complications in the future. This requires understanding target glucose levels for different age groups and making lifestyle changes accordingly, as blood sugar can rise or fall based on what you eat and when, among other factors.
What is an A1c number?
An A1c test, also called glycosylated hemoglobin, is a standard diagnostic tool used to measure a person’s average blood sugar levels over the past three months (90 days). It reflects how well your blood sugar is controlled during that time period.
“It is an essential measure of blood sugar control in diabetes because it provides a long-term view of blood sugar levels and can help predict the risk of diabetes complications,” explains Peralta.
The test uses a small blood sample to analyze the amount of hemoglobin, a protein found in red blood cells that carries oxygen and binds to glucose molecules. The higher the glucose level in the bloodstream, the more hemoglobin will bind to it and be detected by the A1C test. This test is often done with a finger prick in the doctor’s office.
An A1c number is expressed as a percentage, with higher percentages indicating higher blood glucose levels. A healthy A1c reading for a person without diabetes is between 4% and 5.7%. A value between 5.7% and 6.4% is considered prediabetic, while 6.5% and above are consistent with diabetes.
An important note to consider about your A1c number is that it could be affected by other medical conditions such as anemia, which could result in an inaccurate reading. This is why it’s usually recommended to look at additional numbers, such as your fasting glucose, along with an A1c number.