Glucose, or blood sugar, is a type of simple carbohydrate. If your blood sugar levels dip too low (hypoglycemia) or grow too high (hyperglycemia), they can affect your body’s everyday functioning.

Dietary glucose is a monosaccharide (simple sugar), making it the simplest type of carbohydrate (carb).

When you consume dietary glucose, your body converts it into blood glucose. This is one of your body’s primary fuel sources, along with fat and protein.

You can get glucose from simple and complex carb sources, such as:

• white bread, rice, and pasta
• candy
• soda
• syrup
• table sugar
• brown rice
• oats
• fruit
• vegetables
• whole grains

According to the American Heart Association, the body digests complex carbs more slowly than simple carbs, making them a healthier and steadier energy source.

If you’re living with diabetes, perhaps more important is that complex carbs release glucose into the bloodstream gradually rather than immediately. This makes them less likely to cause blood glucose spikes.

Unmanaged glucose levels may have permanent and severe effects.

Keep reading to learn more about glucose and how to measure and manage your blood glucose levels.

Your body ideally uses glucose multiple times per day.

When you eat, your body quickly starts processing glucose and other carbohydrates. Then, enzymes begin to break them down with help from the pancreas.

The pancreas plays a key role in the way your body metabolizes glucose.

When blood glucose levels increase, the pancreas releases a hormone called insulin. This manages the rising blood sugar level by getting glucose into your cells.

Then, muscle, fat, and other cells use glucose for energy or store it as fat for later use.

If your pancreas doesn’t produce insulin the way it should, you may develop diabetes. In this case, you may need medical treatment to help process and regulate glucose in the body.

Insulin resistance

A 2018 review suggests that diabetes may also occur from insulin resistance. This is when the body’s cells do not sense insulin, and too much sugar remains in the bloodstream.

When the body doesn’t respond to insulin the way it should, it stops glucose from entering your cells and being used for energy. Your cells respond by signaling the creation of ketones, which occurs at night and during fasting or dieting.

Over time, insulin resistance may lead to low insulin levels, according to the American Diabetes Association (ADA). Your body may also release fat from fat cells, and the liver will keep releasing ketones, lowering your blood pH to an acidic level.

This typically occurs in type 1 diabetes, where there’s little to no insulin production.

In type 2 diabetes, insulin levels do eventually decrease, but typically not to a level that raises ketones high enough to cause the blood to be acidic.

When your body cannot use glucose properly, the buildup of ketones and changes in blood pH may lead to ketoacidosis. This is a severe, life threatening complication of diabetes that requires immediate medical treatment.

Ketogenic diet and diabetes

The keto diet has gained popularity, but it’s a medical diet with risks.

According to a 2019 study, a low carb or keto diet may reduce body weight, but people with diabetes and taking certain medications may have an increased risk of developing ketoacidosis.

Everyone may experience other adverse effects, such as high cholesterol, which is associated with cardiovascular disease.

It’s best to speak with your doctor before starting any diet plan to help prevent complications.

Was this helpful?
Share on Pinterest
Getty Images

Monitoring glucose levels is important for people with diabetes.

A simple blood test called a blood glucose meter is one of the most common ways to test glucose at home when living with diabetes, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).

Here’s how to use a blood glucose meter:

  1. Using a small lancet needle, prick the side of your fingertip to produce a drop of blood.
  2. Apply the blood to a testing strip.
  3. Place the strip into a meter.
  4. The meter shows how much glucose is in your blood at that moment.

Working with a doctor to help set your glucose goals is important, as these depend on factors like your condition, age, and health history.

How often should you check your blood sugar levels?

Your needs, goals, and treatment plan may dictate how often and when to check your blood sugar level.

To stay on top of your glucose levels, speak with a doctor about when and how frequently you should check your levels. They may suggest checking your levels at the following times:

  • before and after meals
  • before and after exercise
  • during long or intense exercise
  • before bedtime
  • when starting new medications or a new insulin schedule
  • when starting a new work schedule
  • when traveling across time zones

Continuous glucose monitoring

When managing diabetes, you may consider using a continuous glucose monitoring (CGM) system. The device automatically tracks your glucose 24 hours per day and alerts you when it gets too high or low.

According to the NIDDK, the benefits of a CGM include:

  • needing fewer finger pricks
  • helping better manage glucose
  • leading to fewer emergencies

Maintaining healthy blood glucose levels is vital to keep your body functioning. If you’re living with diabetes, you may have to be more diligent.

Blood glucose levels are measured in a fasting state, which is 8 hours after your last meal, or 2 hours after eating. They’re presented in milligrams per deciliter (mg/dL).

Here are the blood glucose ranges to diagnose diabetes, according to the NIDDK:

FastingAfter eating
Normal99 mg/dL or below139 mg/dL or below
Prediabetes100–125 mg/dL140–199 mg/dL
Diabetes126 mg/dL or above200 mg/dL or above

Target blood glucose levels for people with diabetes will vary for each individual. These may differ from the NIDDK’s numbers listed above, which are for the diagnosis of diabetes.

For example, the ADA suggests a blood glucose target of 80–130 mg/dL for people with diabetes.

Your doctor will work with you to come up with your target goals.

What happens if your levels are too low or too high?

Hypoglycemia occurs when your glucose level is too low and dips under 70 mg/dL.

Hyperglycemia happens when your body lacks enough insulin or cannot use it properly. If you have diabetes, this may occur when your blood glucose is greater than the upper limit of your target range, or 130 mg/dL before a meal or 180 mg/dL 1–2 hours after eating.

It’s important to speak with your doctor if you experience symptoms of hypoglycemia or hyperglycemia. If left untreated, both conditions could be fatal.

Was this helpful?

According to the Centers for Disease Control and Prevention (CDC), the following factors may increase blood sugar levels:

As your day goes on, your body’s ability to manage glucose becomes more difficult. Early in the morning, the surge of hormones might cause a spike in blood sugar, called the dawn phenomenon.

Over time, poorly managed glucose levels may negatively affect your body and lead to complications, including:

A condition known as hypoglycemia unawareness may occur with repeated episodes of low blood glucose. It causes you to stop noticing the signs of low blood glucose until it drops very low. When it gets too low, you may experience:

  • loss of consciousness
  • coma
  • death

If you suspect you have diabetes, speak with your healthcare professional about your symptoms.

What does glucose do to your body?

Glucose is the simplest type of carbohydrate. When you consume it, it gets metabolized into blood glucose, which your body uses as a form of energy.

What does it mean when your glucose is high?

High glucose means your blood sugar levels are above 125 mg/dL when fasting. That said, high glucose ranges may vary if you’re living with diabetes. Speak with a healthcare professional if you’re unsure about your blood glucose target range.

Is glucose and sugar the same thing?

Glucose is a simple type of sugar that our body uses for energy. Other types of sugar include fructose, galactose, and lactose, among others.

What is a simple definition of glucose?

Glucose is the simplest type of sugar. Our bodies process it, store it in our cells, and then use it as an energy source to function.

Glucose is the simplest type of carb. When you consume it, it turns into blood glucose, which your body uses as energy.

However, some people experience high blood glucose levels, which may cause diabetes.

If you’re living with diabetes, closely monitoring your glucose levels is an effective way to help avoid complications.

A healthcare professional could help establish a treatment plan that’s right for you.