What is high blood sugar in diabetes?

High blood sugar (hyperglycemia) most often occurs in people who have diabetes that isn't well controlled. The symptoms of high blood sugar can be mild, moderate, or severe.

Mild high blood sugar

You may have mild symptoms if your blood sugar levels are consistently higher than your target range. Some people may not notice any symptoms when their blood sugar level is in this range.

The main symptoms of mild high blood sugar are:

• Increased thirst.
• Increased urination.
• Weight loss.
• Fatigue.

Moderate to severe high blood sugar

You may have moderate to severe symptoms if your blood sugar levels are consistently high. These symptoms include:

• Blurred vision.
• Extreme thirst.
• Lightheadedness.
• Flushed, hot, dry skin.
• Restlessness, drowsiness, or difficulty waking up.

People with type 1 diabetes and some people with type 2 diabetes produce little or no insulin. These people may also have:

• Rapid, deep breathing.
• A fast heart rate and a weak pulse.
• A strong, fruity breath odor.
• Loss of appetite, belly pain, and/or vomiting.

If your blood sugar levels continue to rise, you may:

• Become confused and sluggish.
• Pass out (lose consciousness) if your blood sugar levels are very high.

You can take steps to lower your blood sugar level if you understand what makes it get higher. Your doctor may want you to learn how to test your blood sugar level at home. Then you can see how illness, stress, or different kinds of food or medicine raise or lower your blood sugar level.

Other tests may be needed to see if you have diabetes.

• Watch your weight. If you're overweight, losing just a small amount of weight may help. Reducing fat around your waist is most important.
• Limit the amount of calories, sweets, and unhealthy fat you eat. Ask your doctor if a dietitian can help you. A registered dietitian can help you create meal plans that fit your lifestyle.
• Get at least 30 minutes of exercise on most days of the week. Exercise helps control your blood sugar. It also helps you maintain a healthy weight. Walking is a good choice. You also may want to do other activities, such as running, swimming, cycling, or playing tennis or team sports.
• If your doctor prescribed medicines, take them exactly as prescribed. Call your doctor if you think you are having a problem with your medicine. You will get more details on the specific medicines your doctor prescribes.

If your blood sugar is often higher than your target range, your doctor may do tests to check your blood sugar and ketones. If you take diabetes medicine, the doctor may ask how often you take it. You may be asked about your eating, activity, and other medicines you take that could affect blood sugar.

Sugar (glucose) can build up in your blood if you:

• Have insulin resistance.
• Don't take enough insulin or miss a dose of your diabetes medicine.
• Take certain medicines, such as steroids.

Your body turns the food you eat into glucose (sugar), which it uses for energy. But if your body isn't able to use the sugar right away, it can build up in your blood and lead to high blood sugar.

When the amount of sugar in your blood stays too high for too much of the time, you may have diabetes. Diabetes is a disease that can cause serious health problems.

The good news is that lifestyle changes may help you get your blood sugar back to normal and avoid or delay diabetes.

After your blood sugar level has returned to a target range:

• Continue medicine as prescribed by your doctor.
• Check blood sugar levels as directed.
• Report the episode to your doctor.
• Drink extra liquids to replace the fluids lost through urine.
  • Water and sugar-free drinks are best.
  • Avoid caffeinated drinks and alcohol. Also avoid regular soda pop, fruit juice, and other liquids that contain a lot of sugar.