"Normally a person with an injury on the bottom of their foot, such as a blister, will change the way they walk. Your gait will alter because you are going to protect that blistered spot until it heals up," says Joseph LeMaster, MD, an assistant professor at the University of Missouri–Columbia School of Medicine.
"People with a loss of sensation don't do that. They will just walk right on top of that blister as though it wasn't there. It can burst, become infected, and turn into what we call a foot ulcer," he says. "That ulceration can go right down to the bone and become an avenue for infection into the whole foot. That's what leads to amputations."
Foot injuries are the most common cause of hospitalizations
About 15% of all diabetics will develop a foot ulcer at some point and up to 24% of people with a foot ulcer need an amputation. You're at extra-high risk if you're black, Hispanic, or Native American. These minority populations are two to three times more likely to have diabetes than non-Hispanic whites, and their rates of amputations are higher.
About a year ago, Dr. Armstrong treated a 59-year-old man with type 2 diabetes who had been working out at a local health club; 12 hours later, he discovered a screw from a piece of gym equipment lodged in his foot.
"This isn't a dummy. He's a sweetheart of a guy," says Dr. Armstrong. "It's just that he doesn't have the gift of pain, and that's what's so profound." Ultimately the man's toes were amputated, but he is able to walk and work out with close monitoring, Dr. Armstrong said.
Check your feet daily
"The single most important thing that a person with diabetes can do to prevent a problem is to look at their feet every day, just as they comb their hair or brush their teeth," says Dr. Armstrong. You can use a mirror to examine your feet or have a family member check your feet for you.
An increase in the temperature of your foot, which can be detected with a special infrared thermometer, can be an early sign of trouble. "The foot will get hot before the skin breaks down," says Dr. Armstrong.
In a study published in 2007 of 225 patients, which was conducted by Dr. Armstrong and colleagues, half of the patients checked the temperature in six places on each foot twice daily and half examined their feet visually. If there was more than four degrees' difference between the left foot, the thermometer-using patients contacted their doctor.
At the end of the 18-month study, about 5% of patients who used the thermometer developed a foot ulcer compared to 12% of patients who did not. (Dr. Armstrong owns stock in the themometer manufacturer, Xilas Medical, and is a former consultant for the company.)
Other ways to prevent foot problems
Here are more tips on preventing foot problems from the National Diabetes Education Program.
- Quit smoking if you're a smoker. Smoking is considered a likely factor in diabetic foot disease.
- Be super-vigilant about your controlling your blood sugar. According to results of the United Kingdom Prospective Diabetes Study, people with type 2 diabetes who lower their blood glucose through intensive therapy are at reduced risk for neuropathy.
- Choose shoes carefully.
- Cut your toenails carefully or have someone else do it if you already have numbness.