Hyperglycemia means high levels of blood sugar (blood glucose). Over time, it can cause major health complications in people with diabetes.

Several factors can contribute to hyperglycemia, including dietary choices and a sedentary lifestyle.

Regular blood glucose testing is crucial for people with diabetes. This is because many people don’t feel the effects of hyperglycemia.

According to the Centers for Disease Control and Prevention (CDC), target blood glucose levels for people with diabetes are typically:

  • between 80 and 130 milligrams per deciliter (mg/dL) before you’ve eaten
  • under 180 mg/dL 2 hours after the first bite of your meal

Blood sugar levels that are higher than that may indicate hyperglycemia.

However, you may not feel the effects of hyperglycemia until your blood glucose levels are very high for an extended period of time. If you experience symptoms of hyperglycemia, it’s important that you check your blood glucose levels.

Hyperglycemia symptoms that may develop over several days or weeks include:

The longer the condition is left untreated, the more severe it may become. Long-term effects of hyperglycemia include:

  • eye disease
  • kidney disease
  • cardiovascular disease
  • neuropathy, or nerve damage

A number of things can contribute to hyperglycemia, including:

  • not getting the right dosage of insulin or other glucose-lowering medication
  • eating more carbohydrates than usual
  • being less physically active than usual
  • illness or infection
  • high levels of stress
  • physical trauma, such as an orthopedic injury

Risk factors for hyperglycemia include:

Several treatments are available for hyperglycemia.

Monitor your glucose levels

An important part of managing your diabetes is checking your blood glucose levels often, such as before you eat, after you eat, or at bedtime.

You should then record that number in a notebook, blood glucose log, or blood glucose tracking app so you and your doctor can monitor your treatment plan.

Knowing when your blood glucose levels are getting out of your target range can help you get your blood glucose back on track before more significant complications arise.

Get moving

Exercise is one of the best and most effective ways to keep your blood glucose levels where they should be and lower them if they get too high.

If you’re on medications that increase insulin, talk with your doctor to determine the best times to exercise. If you have complications such as nerve or eye damage, ask your doctor which exercises might suit you best.

An important note: If you have had diabetes for an extended period of time and are on insulin therapy, talk with your doctor to see if there are any exercises you should limit when your blood glucose levels are high.

For example, if your blood glucose level is above 240 mg/dL, your doctor may have you check your urine for ketones.

Don’t exercise if you have ketones. Your doctor may also tell you not to exercise if your blood glucose is above 300 mg/dL even without ketones.

Exercising when ketones are in your body may cause your blood glucose level to rise even higher. While it’s rare for those with type 2 diabetes to experience this, it’s still best to be cautious.

Analyze your eating habits

Work with a dietitian or nutritionist to construct a nutritious, interesting selection of meals that can help you manage your carbohydrate intake and prevent higher blood glucose levels.

Diet plans you may want to explore include:

Evaluate your treatment plan

You doctor may reevaluate your diabetes treatment plan based on your personal health history and your experiences with hyperglycemia. They may change the amount, type, or timing of your medication.

Don’t adjust your medications without first talking with your doctor or diabetes educator.

Untreated and chronic hyperglycemia can cause both minor and serious complications.

Complications include:

HHS is a rare condition that appears most often in older adults with type 2 diabetes. It may be accompanied by a trigger, such as an illness.

When blood glucose levels are high, the kidneys excrete sugar into the urine, taking water with it. This causes the blood to become more concentrated, resulting in high sodium and blood glucose levels.

If left untreated, HHS may lead to life threatening dehydration and even coma.

A few lifestyle changes may help prevent you from developing hyperglycemia. Try the tips below:

  • Test yourself regularly. Test and record your blood glucose levels on a regular basis each day. Share this information with your doctor at every appointment.
  • Manage your carb intake. Know how many carbohydrates you’re getting with each meal and snack. Strive to stay within the range approved by your doctor or dietitian. Keep this information with the records of your blood glucose levels.
  • Be diabetes smart. Have an action plan for if and when your blood glucose reaches certain levels. Take your medication as prescribed, being consistent about the amount and timing of your meals and snacks.
  • Have alcohol in moderation. Although hypogylcemia is a more likely outcome, drinking large amounts of alcohol can eventually lead to high blood glucose levels. If you’re having alcohol, choose a drink that’s low in carbs and sugar.
  • Wear medical identification. Medical bracelets or necklaces can help alert emergency responders to your diabetes if there’s a greater problem.

You probably won’t feel the effects of hyperglycemia right away. Over time, though, it can cause noticeable symptoms, such as thirstiness and excessive urination.

If the hyperglycemia isn’t properly treated, you can even develop DKA or HHS. Both of these conditions are considered medical emergencies.

Know the symptoms of hyperglycemia and these related conditions, and make it a habit to regularly check your blood glucose levels. Good diabetes management and careful monitoring of your blood glucose levels are both very effective means for preventing hyperglycemia or stopping it before it gets worse.