Foot and ankle surgeons say those symptoms may be caused by a condition called diabetic peripheral neuropathy, or nerve damage. Neuropathy in the feet can lead to permanent numbness, deformities such as bunions and hammertoes, and dry skin that cracks open and won't heal.
"Diabetic peripheral neuropathy is not only painful but dangerous," says Boston foot and ankle surgeon John M. Giurini, DPM, FACFAS, president of the 6,000-member surgeons' association. "It's a leading contributor to foot ulcers in people with diabetes."
Burning, tingling and numbness in the toes can also be symptoms of thyroid problems, nutritional deficiencies, back problems and pinched nerves in the ankles. In the United States, diabetes is the leading cause of peripheral neuropathy and can lead to further foot complications.
Out of the 23 million Americans with diabetes, one in four hasn't been diagnosed. Some people learn they have diabetes only after seeing a doctor for burning, tingling and numbness in their toes and feet. Many people already diagnosed with diabetes aren't familiar with neuropathy's symptoms. According to FootPhysicians.com, even diabetic patients who have excellent blood sugar control can develop diabetic neuropathy.
Medications can treat neuropathy pain. But nerve damage cannot be reversed.
"When you have diabetes, and especially diabetic neuropathy, a minor cut on your foot can turn into a catastrophe," says Giurini. "The statistics on diabetic ulcers are sobering."
Twenty percent of diabetes patients who develop ulcers will require an amputation. Patients who are black, Hispanic and Native American are twice as likely as whites to need a diabetes-related amputation. Half of all people with diabetes who have a toe or foot amputation die within three years. The annual cost for diabetic ulcer care in the U.S. is estimated at $5 billion.