What is Blood Sugar—and Why Does it Matter?

What is...blood sugar?

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, 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 Type 2 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.

What is blood sugar?

Blood sugar is the concentration of sugar (glucose) in a person’s blood — usually measured as the collective weight of the sugar (milligrams (mg)) present in twenty teaspoons of blood (deciliter (dL). 

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

However, 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. 

What is a healthy blood-sugar level?

Maintained at about 80-120mg/dL, blood-sugar levels are generally considered to be within normal and healthy levels.

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 is more sugar than 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).

It can also 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, doctors 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.


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