What is high blood sugar?

High blood sugar, also called hyperglycemia, happens when there is too much glucose in the bloodstream. It is most common in people with diabetes, but it can also happen during illness, stress, or while taking certain medications.

When blood sugar stays high for too long, it can affect many parts of the body. Without treatment, severe hyperglycemia may lead to serious complications that require emergency care.

Several factors can cause blood sugar levels to rise, including:

• Missed insulin or diabetes medications
• Illness or infection
• Emotional or physical stress
• Eating more carbohydrates than usual
• Reduced activity levels
• Certain medications, such as steroids

Symptoms

High blood sugar can develop slowly or happen suddenly. Some people notice symptoms right away, while others may not realize their blood sugar is elevated until it becomes more severe.

Common symptoms may include:

• Feeling very thirsty
• Frequent urination
• Dry mouth
• Fatigue or low energy
• Blurred vision
• Headaches
• Nausea or vomiting
• Belly pain
• Weakness or dizziness
• Slow-healing cuts or infections
• Unexplained weight loss
• Fruity-smelling breath or rapid breathing in severe cases

How is it diagnosed?

Healthcare providers diagnose high blood sugar by checking glucose levels in the blood. This may include a finger-stick blood sugar test, continuous glucose monitoring, or an A1C test that measures average blood sugar over time.

Your provider will also review your symptoms, medications, and overall health. If blood sugar levels are very high, urine or blood ketone testing may be needed to check for serious complications.

How is it treated?

Treatment depends on how high the blood sugar is and what is causing it. Many people can improve mild hyperglycemia by following their diabetes care plan closely.

Treatment may include:

• Taking diabetes medications or insulin as prescribed
• Drinking plenty of water or sugar-free fluids
• Monitoring blood sugar more often
• Following a balanced meal plan
• Staying physically active when safe
• Managing illness or stress

If blood sugar remains very high or symptoms become severe, emergency medical treatment may be needed. Quick care can help prevent dehydration and other dangerous complications.

Long-term management focuses on keeping blood sugar in a healthy range to reduce the risk of future problems.