Persistent and abnormally high blood glucose is a condition resulting from diabetes mellitus. Insulin is necessary for the metabolism of glucose. Elevated blood glucose or sugar, called hyperglycemia, develops when there is either too little insulin or when the insulin is not effective, according to Medline Plus. High blood glucose can result in many serious complications.
Nerve Damage
People with continual high blood glucose can develop nerve damage called neuropathy, reports the National Diabetes Information Clearinghouse (NDIC). You would usually feel this as numbness and tingling in your extremities, and it's called peripheral neuropathy. Because nerve damage can occur anywhere in the body, symptoms of muscle weakness and pain, changes in bowel and bladder function, and changes in sexual response can develop, according to the NDIC.
Eye Damage
Sustained high blood sugar eventually has detrimental effects on several parts of the eye. High blood glucose can damage the retina, lens, optic nerve and eye fluid, says the NDIC. Harm to the retina, called retinopathy, is the most common problem associated with an elevated blood glucose level, and can eventually lead to blindness, according to the NDIC
Kidney Damage
One of the most common causes of chronic kidney failure in the United States is due to diabetes, notes Merck.com. High blood sugar causes injury to the small vessels of the kidney, damaging its filtering capability, and resulting in water retention and loss of protein in the urine, according to The National Kidney Foundation. High blood sugar also injures the nerves supplying the bladder, which can cause urine to back up into the kidneys.
Cardiovascular Disease
A prolonged high blood glucose level leads to plaque build up in the blood vessels, and increases your risk for heart attacks and strokes, according to the NDIC. The NDIC also notes that poor circulation results from fatty deposits blocking and narrowing the blood vessels.
Infections
Because of hyperglycemia's effect on white blood cell function, diabetics are especially prone to infections, particularly fungal and bacterial infections, according to Merck.com. Poor circulation due to damaged nerves and small blood vessels increases the risk of infections in the feet and legs.
Ketoacidosis
Ketoacidosis is a dangerous and sometimes life-threatening condition brought on by an inability to burn glucose as fuel. To meet energy requirements, the body begins to burn fat for fuel instead of glucose. The breakdown products of fats are acid products known as ketone bodies. Very high levels of these ketones results in an acidic condition in the body, according to Battle Creek Health System. Some of the symptoms of ketoacidosis are fatigue, nausea and vomiting, stomach pain, difficulty breathing and fainting.
