Skip to Main Content

What is blood sugar?

General health

What is...blood sugar?

What it is and why it matters.

Sugars fuel the human body, powering our every thought and movement. Whether the sugars in our bodies come from fruit, potatoes, or a bar of dark chocolate sitting, the sugars we consume are critical for our well-being. They can also be seriously detrimental. Too much added sugar can increase your risk of serious health conditions — such as cardiovascular disease and diabetes — which is why monitoring our sugar levels is essential to our health. To do this, we (and our doctors) focus on something known as blood sugar.

In its most basic meaning, “blood sugar” is a term that describes the concentration of sugar in a person’s blood — usually measured as the collective weight of the sugar (milligrams (mg)) present in twenty teaspoons of blood (deciliter (dL)). In this case, sugar is specifically referring to a type of sugar known as glucose. Glucose is a very important molecule because its molecular bonds are packed with energy. Our bodies use this energy to help us breathe, help our muscles contract, and even help us think. For this reason, glucose is needed in every organ of the human body. 

To satisfy this need, we eat sugars; though, we rarely eat glucose. Instead, we eat complex sugars that are made of multiple glucose molecules strung together and transformed in various ways. Once consumed, these complex sugars are shattered into basic fragments, usually in the form of glucose. 

Blood sugar levels are generally considered to be within normal, healthy levels maintained at about 80-120mg/dL. But these levels also typically vary under different conditions. For example, glucose levels in the blood tend to rise after we eat a meal. If there’s more sugar than is needed in the food we eat, the body will deposit the glucose in muscle and liver tissues for short term storage (it goes to fat tissues for long term storage). In moments of fasting, such as when we’re sleeping, we get energy from these storage depots. All of this is a natural, coordinated effort by the body to ensure that our cells have access to the energy our bodies need, but not so much that it would cause damage.

Some people, however, have greater difficulty controlling their blood sugar levels. This can be caused by genetic factors, as is the case for Maturity Onset Diabetes of the Young (MODY), or it can result from a progressive deterioration of the body’s ability to remove sugar from the blood, which is seen in type 1 and 2 diabetes. In addition to diabetes, over time, blood sugar levels that are out of balance can result in cardiovascular disease, vision loss, and other serious health conditions.

To prevent these issues, doctors often like to measure blood sugar levels as part of routine physical exams. By tracking the amount of glucose in your blood over time, they can see if it’s persistently high, low, or average. If your levels are anything other than average, it may point to a developing problem that requires further exploration and potentially therapeutic intervention. Ultimately, monitoring blood sugar is a tool that enables preventative action, which can help you  live a healthier life.