Health Effects of High Blood Sugar

High blood sugar (hyperglycemia) is a primary symptom of diabetes. When glucose levels rise, symptoms such as increased hunger or thirst, blurred vision, headache or fatigue may occur, indicating need for treatment. If left untreated, hyperglycemia can lead to numerous detrimental health effects. To prevent complications of hyperglycemia, seek prompt medical guidance as soon as you notice symptoms.

Neuropathy (Nerve Damage)

Neuropathy refers to nerve damage throughout the body. Frequent or recurrent high blood sugar commonly causes neuropathy. According to the National Diabetes Information Clearinghouse, 60 to 70 percent of people with diabetes have some form of neuropathy. Though the condition may arise at anytime, age, duration of diabetes and excess body weight increase a person’s risk and those who’ve had diabetes more than 25 years are at greatest risk. Nerve damage may occur in every organ system, including the digestive tract, heart and sex organs. If you experience common symptoms of nerve damage, such as pain, tingling and numbness in the hands, arms, feet or legs, seek guidance from your doctor. Treatment often includes improving blood sugar levels and reducing pain with medication.


A cataract, or clouding of the lens of your eye, may cause blurred or cloudy vision, making tasks such as reading and driving difficult. Chronic high blood sugar increases your risk of developing cataracts. According to the American Diabetes Association, people with diabetes are 60 percent more likely to develop cataracts than people without diabetes. Cataracts usually develop slowly and do not cause pain. If left untreated, or if treated after the cataracts have developed substantially, surgery is often required to remove the top layer of the eye. In mild cases, specialized glasses may improve cataract symptoms. Managing blood sugar through a healthy diet, doctor-approved exercise and taking medications properly can help reduce the risk of developing cataracts. If you notice symptoms of cataracts, such as sensitivity to light, reduced night vision or seeing halos (glare) around lights, seek prompt testing from your doctor or ophthalmologist.

Diabetic Ketoacidosis

If your blood sugar remains high for an extensive amount of time, you may develop diabetic ketoacidosis, a life threatening condition. When blood sugar levels rise and you have too little insulin in your body, the body attempts to break down fat to use for energy. In doing so, your body produces toxic acids called ketones. If left untreated, diabetic ketoacidosis can result in diabetic coma or death. According to the American Diabetes Association, ketoacidosis can occur for anyone with diabetes, though it is rare in people with type 2 diabetes. Initial symptoms of ketoacidosis include a very dry mouth, frequent urination, high blood sugar and ketones in the urine. (Some people with diabetes utilize ketone testing strips, available at most drug stores.) You may also feel lethargic, nauseous, have difficulty breathing or notice a fruity smell to your breath. If you observe any symptom of ketoacidosis, seek immediate medical attention.

About this Author

August J. McLaughlin is a certified nutritionist and health writer with more than nine years of professional experience. Her work has been featured in various magazines such as “Healthy Aging,” “CitySmart,” “IAmThatGirl” and “ULM.” She holds specializations in eating disorders, healthy weight management and sports nutrition. She is currently completing her second cookbook and Weight Limit – a series of body image/nutrition-related PSAs.