What Are the Side Effects of High Blood Sugar Levels?

Close-up of a woman performing a blood sugar test.
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High blood sugar, also known as hyperglycemia, occurs when the body has too little insulin, or cannot use it properly. Common causes of high blood sugar include overeating, under-exercising and emotional stress. According to the American Diabetes Association (ADA), hyperglycemia is a major cause of complications for people diabetes. If you experience frequent or extreme symptoms of high blood sugar, seek guidance from your doctor.

Frequent Urination

Frequent urination is a common symptom of high blood sugar. Urinating more frequently or producing greater urine volume than usual, regardless of how much fluid you've consumed, is often a first recognized symptom of diabetes. When blood sugar increases, compounds known as ketones may develop in the body. Urine test strips provide a means of testing ketone levels at home. According to the ADA, exercise can lower blood sugar. However, if you know that your blood sugar is high and your ketone level is high, exercise may further elevate blood sugar. Reducing your food intake may also help manage your blood sugar. If you have not been tested for, or diagnosed with, diabetes and experience on-going frequent urination, discuss your symptoms with your doctor.


Increased Thirst and Hunger

Unexplained increases in thirst and hunger may indicate high blood sugar. According to the University of Iowa Hospitals and Clinics (UIHC), dry mouth and increased thirst are common first symptoms of ketoacidosis, a condition also known as diabetic coma. Ketoacidosis occurs when the body lacks insulin and cannot utilize glucose as fuel. The body breaks down fats to use as energy, which causes ketone production. Too many ketones cause build-up, the precursor to ketoacidosis. People with diabetes often recognize the symptoms of high blood sugar, such as thirst, before ketoacidosis happens. In severe cases, ketoacidosis can develop quickly. For people who have diabetes without realizing it, symptoms such as hunger and thirst can serve as useful red flags, indicating that doctor's examination and care are needed. Whether or not you have diabetes, discuss unusual thirst and hunger symptoms with your doctor to best preserve your wellness.


Blurry Vision or Lethargy

Blurry vision can occur as a symptom of high blood sugar. According to the UIHC, people with undiagnosed diabetes may also experience fatigue and tiredness. In addition, those undiagnosed may experience unexplained weight loss, nausea or vomiting. People diagnosed and undergoing treatment or management for diabetes, who fail to take medications or eat properly, are likely to experience high blood sugar. Once symptoms of vision or energy changes are observed, the patient will likely follow treatment protocol as designated by his doctor, such as administering insulin injections. If you or a loved one struggles with blood sugar management, discuss your concerns with your doctor. If your symptoms become severe, seek emergency medical care promptly. To further improve your chance of reaping immediate and proper medical care, consider wearing a medical bracelet that indicates crucial information regarding your condition.


Is This an Emergency?

If you are experiencing serious medical symptoms, please see the National Library of Medicine’s list of signs you need emergency medical attention or call 911. If you think you may have COVID-19, use the CDC’s Coronavirus Self-Checker before leaving the house.