Diagnosing Diabetic Foot Ulcers

A foot ulcer is an open sore that develops as a complication of diabetes. Diabetic foot specialists at NYU Langone determine the severity of an ulcer and whether other complications of diabetes may prevent it from healing.

Ulcers often affect people with diabetes who have peripheral neuropathy, lower extremity arterial disease, or both. Peripheral neuropathy is nerve damage that reduces sensation in the legs and feet. It can prevent a person from feeling the pain of a blister or other injury on the foot.

Lower extremity arterial disease reduces blood flow to the legs and feet. This means the injury may not receive adequate blood supply, which can delay healing.

If an injury goes unnoticed, it may quickly progress from a small blister or cut to an ulcer. Without treatment, ulcers may become infected because of exposure to germs and bacteria.

It’s important to know that diabetic foot ulcers can be preventable. Daily cleaning and foot inspection and wearing shoes that fit well can help keep your feet healthy.

Doctors at NYU Langone diagnose a foot ulcer during a physical exam. If needed, your doctor may recommend one or more diagnostic tests to obtain more information about the injury.

Based on the results, our experts in wound care, vascular surgery, and orthopedic surgery provide customized treatment to help you fully recover and stay healthy.

Medical History and Physical Exam

If you have a foot ulcer, your doctor asks when you first noticed it. He or she also wants to know if you have any other medical conditions, such as peripheral neuropathy or lower extremity arterial disease, which increase the risk of foot ulcers.

Your doctor inspects the foot, toes, and toenails for blisters, cuts, scratches, or ingrown toenails that may lead to additional ulcers. He or she also evaluates the rate of blood flow in the foot by feeling the pulse.

You may be asked to stand and walk so the doctor can assess how the weight of your body is distributed across the bones and joints of the feet. A limp may indicate structural damage, and an uneven gait may cause a blister to form. He or she also evaluates the shape of the foot, since an abnormal alignment may increase the risk of ulcers.

X-ray

Your doctor may recommend X-ray imaging to assess changes in the alignment of the bones in the foot, which can contribute to an ulcer. X-rays can also reveal a loss of bone mass, which may occur as a result of hormonal imbalances related to diabetes.

Low bone mass weakens bones and can lead to repeated small fractures and other injuries in the foot, a condition called Charcot foot. Early detection of this condition can help you avoid permanent misalignment of the foot bones, which can prevent new ulcers from forming.

MRI Scans

MRI scans use a magnetic field and radio waves to create computerized, three-dimensional images of soft tissues inside the body. Your doctor may recommend this test if he or she needs more information about the extent of damage caused by an ulcer. MRI images can also reveal inflammation, which may be a sign of infection.

Blood Test

If there are signs of infection, such as redness, swelling, and warmth in the affected foot, your doctor may recommend a blood test to screen for it. This takes place in a doctor’s office, and the results are usually available within a week.