Glucose testing is a random blood test to check glucose (sugar) levels. It’s usually done by pricking the finger to draw a small drop of blood. This blood is then wiped onto a test strip that will give a glucose reading.

Random glucose testing is a powerful tool for people with diabetes. It can help assess how well the disease is being managed.

What is diabetes?

Diabetes is a disease that affects your body’s ability to release insulin from your pancreas once sugars are turned into glucose. The insulin allows the glucose to enter the bloodstream and be used for energy. In diabetes, this function doesn’t work properly.

Some early symptoms of diabetes are excessive urination and thirst. This is caused by the sugar buildup in the blood that isn’t absorbed. It’s filtered out through the kidneys in large amounts, which can then lead to dehydration.

Other symptoms may include:

  • weight loss
  • blurred vision
  • being tired constantly
  • tingling in arms and legs
  • slow healing of wounds

Glucose testing helps keep track of symptoms and manage diabetes. Random blood glucose values vary depending on the last time you ate.

If you’re testing within one to two hours after the start of a meal, the American Diabetes Association (ADA) recommends glucose levels be under 180 mg/dL. Before a meal, the levels can be between 80 and 130 mg/dL.

A fasting glucose reading of less than 100 mg/dL is normal. If the fasting reading is between 100 and 125 mg/dL, there’s a change you have impaired glucose tolerance, otherwise known as prediabetes.

Prediabetes increases the chance that you’ll develop type 2 diabetes. If you have a fasting sugar level over 126 mg/dL, there’s a high chance you have diabetes.

Your doctor may schedule another glucose test for you if it’s positive for diabetes. There are a number of factors that can contribute to an inaccurate reading, like certain medications or illnesses.

If you have diabetes, blood glucose levels are based on age, how long you’ve had the condition, and initial blood tests.

The ADA suggests keeping track of all these results to keep a daily record of blood level history. Stress, activity, and food can make the results vary. Keeping note of what you’re doing or feeling with the levels is also crucial.

If the readings are too high or too low for a number of days in a row, it may be time to consult your doctor. Going over a target level with your doctor and changing the plan can give better results.

In adults without diabetes, glucose levels are managed through the actions of our internal insulin and the body’s use of sugar for energy. If they received random glucose tests throughout the day, their glucose levels would remain relatively stable. This would be true even if they:

  • varied their diet
  • experienced stress
  • ate at different times of the day

In people with diabetes and prediabetes, glucose levels can vary widely over the course of the day. This is particularly true if the disease isn’t managed well. In these people, random test results will vary widely. Tests may also be consistently high.

A random test is one performed outside your normal testing schedule. Random testing is an important part of diabetes management. If random glucose levels are acceptable, your strategy is probably working. Wide swings in your levels suggest you may need to change your management plan.

Remember, high sugar levels are what cause the complications seen with diabetes over time. Symptoms of acute high blood sugar levels include:

If you have diabetes, paying close attention to your symptoms is very important. Be sure to test immediately if you feel you’re experiencing symptoms of low blood sugar. Random blood glucose readings can help you identify hyperglycemia and decrease the risk for some chronic complications.

Testing your blood glucose levels at various times throughout the day can help you manage your diabetes and reduce your risk of diabetes complications. The only way you can know what your blood sugar level is to test it on a regular basis.

Random glucose testing isn’t a substitute for your normal glucose testing schedule. You should also perform fasting tests and tests after meals, as suggested by your doctor.

A fasting blood glucose test is usually performed upon waking, before you eat. Testing after meals measures glucose levels around two hours after the start of a meal. Different testing times will yield different results. These are affected by:

  • the food you’ve eaten
  • stress
  • medications you’re taking
  • any exercise you’ve done

For some people, it’s important to test every day. This helps you get a sense of your overall blood sugar control and can help you make treatment decisions. Testing is the best way to learn how your blood sugar is affected by your lifestyle, medications, or both.

Exercise can play a role in your random glucose test results. Generally, exercise will lower glucose levels. It may even require you to adjust your insulin regimen if you’re on intensive insulin therapy.

This shouldn’t discourage you from exercising. Exercise is one of the best ways you can help control diabetes. Most people with diabetes gain benefits from even moderate exercise.

Exercise increases your body’s ability to use insulin. It also burns extra glucose in your bloodstream. In the long term, exercise will lead to more stable random glucose test results.

Diabetes is a serious condition. There’s no current cure for it, but it can be managed with proper care. The key is healthy behavior changes combined with good glucose monitoring.

If you find that your glucose levels just aren’t getting under control, it’s time to speak with your doctor. You may need to make changes in your management program before further complications arise.