ComplicationsBy Mayo Clinic staff
Untreated hyperglycemia can cause long-term complications. These include:
- Cardiovascular disease
- Nerve damage (neuropathy)
- Kidney damage (nephropathy) or kidney failure
- Damage to the blood vessels of the retina (diabetic retinopathy), potentially leading to blindness
- Clouding of the normally clear lens of your eye (cataract)
- Feet problems caused by damaged nerves or poor blood flow that can lead to serious infections
- Bone and joint problems, such as osteoporosis
- Skin problems, including bacterial infections, fungal infections and nonhealing wounds
- Teeth and gum infections
If blood sugar rises high enough or for a prolonged period of time, it can lead to two serious conditions.
Diabetic ketoacidosis. Diabetic ketoacidosis develops when you have too little insulin in your body. Without enough insulin, sugar (glucose) can't enter your cells for energy. Your blood sugar level rises, and your body begins to break down fat for energy.
This process produces toxic acids known as ketones. Excess ketones accumulate in the blood and eventually "spill over" into the urine. Left untreated, diabetic ketoacidosis can lead to diabetic coma and be life-threatening.
Diabetic hyperosmolar syndrome. This condition occurs when people produce insulin, but it doesn't work properly. Blood glucose levels may become very high — greater than 600 mg/dL (33 mmol/L). Because insulin is present but not working properly, the body can't use either glucose or fat for energy.
Glucose is then dumped in the urine, causing increased urination. Left untreated, diabetic hyperosmolar syndrome can lead to coma and life-threatening dehydration. Prompt medical care is essential.
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