Diabetic neuropathy: Complications
Diabetic neuropathy can cause a number of serious complications, including
Loss of a limb. Because nerve damage can cause a lack of feeling in your feet, cuts and sores may go unnoticed and eventually become severely infected or ulcerated Û a condition in which the skin and soft tissues break down. The risk of infection is high because diabetes reduces blood flow to your feet.
Infections that spread to the bone and cause tissue death (gangrene) may be impossible to treat and require amputation of a toe, foot or even the lower leg. More than half the nontraumatic lower limb amputations performed every year in the United States are due to diabetes.
* Charcot joint. This occurs when a joint, usually in the foot, deteriorates because of nerve damage. Charcot joint is marked by a loss of sensation, as well as swelling, instability and sometimes deformity in the joint itself.
* Urinary tract infections and urinary incontinence. Damage to the nerves that control your bladder can prevent it from emptying completely. This allows bacteria to grow in your bladder and kidneys, leading to urinary tract infections. Nerve damage can also affect your ability to sense when you need to urinate or to control the muscles that release urine.
* Hypoglycemia unawareness. Normally, when your blood sugar drops too low Û below 70 milligrams per deciliter (mg/dL), or below 3.0 millimoles per liter (mmol/L) Û you develop symptoms such as shakiness, sweating and a fast heartbeat. These symptoms alert you to the problem so that you can take steps to raise your blood sugar quickly. Autonomic neuropathy can interfere with your ability to notice these symptoms. This is extremely serious Û untreated hypoglycemia can be fatal.
* Low blood pressure. Damage to the nerves that control circulation can affect your body's ability to adjust blood pressure. This can cause a sharp drop in pressure when you stand after sitting (orthostatic hypotension), which may lead to dizziness and fainting.
* Digestive problems. Nerve damage to the digestive system can cause a range of problems, including severe constipation or diarrhea Û or alternating bouts of constipation and diarrhea Û as well as nausea, vomiting, bloating and loss of appetite. One particularly serious digestive problem is gastroparesis, a condition in which the stomach empties too slowly or not at all. This can interfere with digestion, cause nausea and vomiting, and severely affect blood sugar levels and nutrition.
* Sexual dysfunction. Autonomic neuropathy often damages the nerves that affect the sex organs, leading to erectile dysfunction in men and problems with lubrication and arousal in women.
* Increased or decreased sweating. When the sweat glands don't function normally, your body isn't able to regulate its temperature properly. A reduced or complete lack of perspiration (anhidrosis) can be life-threatening. More often, autonomic neuropathy causes excessive sweating, particularly at night.
* Social isolation. The pain, disability and embarrassment caused by nerve damage can rob people Û particularly older adults Û of their independence, leaving them increasingly isolated and depressed.
Jan. 16, 2008
By Mayo Clinic Staff
