High blood sugar, or hyperglycemia, is characteristic of both types of diabetes. In type 1, beta cells in the pancreas do not secrete insulin in sufficient quantity to regulate blood sugar, or glucose. In type 2, the pancreas may over-produce insulin in an effort to meet increased needs, but since insulin can be damaging to muscles, liver and fat cells they develop a resistance to it. Insulin becomes ineffective and blood sugar rises. Both types of diabetes benefit from careful diet, exercise and regular monitoring. The treatment of type 1 diabetes is dependent on insulin administration to control blood sugar. Oral medications may be recommended for type 2 diabetics. Over time, excessive blood sugar damages blood vessels, organs and nerves.
Cardiovascular Disease
The risk of stroke or heart attack for diabetics is double that of the general public. High blood sugar damages the lining of blood vessels. Fatty substances and calcium build up in the scarred areas, narrowing arteries and raising blood pressure. The heart has to work harder. Coronary artery disease leads to painful angina when the heart muscle is deprived of oxygenated blood. Over time, the cardiac muscle can thicken, leading to heart failure.
A heart attack, or the death of cardiac tissue from lack of circulation, is caused by a blood clot in the heart. The brain is also susceptible to damage, called a stroke, when a blood clot blocks circulation. A stroke may also be caused by damaged blood vessels which break and bleed in the brain. Stroke victims may be left with permanent loss of speech and memory and one-sided paralysis.
Blindness
Cataracts, or the clouding of the lens of the eye, develop at an earlier age in diabetics. Poorly controlled blood sugar can also lead to glaucoma, an increase of fluid pressure that damages nerves, causing vision loss. Diabetic retinopathy is a leading cause of adult blindness in the United States, according to the National Eye Institute. It is caused by damage to and blockage of blood vessels that nourish the retina of the eye.
Neuropathy
Normally, nerve cells in the extremities and digestive tract are nourished by small blood vessels, or capillaries. Over time, high blood sugar damages the lining of the capillaries and nerve cells die or are damaged. Digestive problems may result. Pins and needles sensations may be felt in the fingers and toes. Nerve damage causes pain, or neuropathy, and loss of sensation, particularly in the legs and feet. High blood sugar's effects on circulation, coupled with a loss of sensation, makes the lower limbs vulnerable to wounds that don't heal or become infected. Poorly managed diabetes leads to surgical remedies and sometimes amputation.
Kidney Failure
The National Kidney and Urological Diseases Information Clearinghouse lists diabetes as the cause of 44 percent of new cases of kidney failure a year. Also called end-stage renal disease, treatment is limited to dialysis and kidney transplant. Damage to kidney tissues caused by high blood sugar starts slowly and may have no symptoms. Doctors look for the presence of albumin, or protein, in the urine, and higher than normal levels of creatinine to detect developing kidney disease.
