Foot ulcers and pressure ulcers can cause pain. However, people with both types of ulcer often feel no symptoms because neuropathy has caused nerve damage that reduces or eliminates sensation.

Regular self-monitoring and appointments with a physician play important roles in containing ulcers. Visual inspection is crucial for detecting foot and pressure ulcers in time to prevent complications.

Diagnosis of an ulcer usually involves a physician’s visual inspection. In the case of a pressure ulcer, the physician also diagnoses the severity by examining the site and noting the extent of damage. There are six stages of ulcers (decubiti):

• Stage 1: Skin is red but unbroken.
• Stage 2: Skin is swollen, often has blisters.
• Stage 3: The sore has ulcerated, revealing deeper layers of skin.
• Stage 4: The sore extends into muscle.
• Stage 5: Muscle is destroyed.
• Stage 6: Bone is exposed, damaged, possibly infected.

In addition, physicians may perform one or more tests to identify an underlying condition that might be contributing to ulcer formation, including:

• Monofilament test. A fast and painless check of sensation that can be used to diagnose peripheral neuropathy. It uses a device consisting of a nylon filament mounted on a holder. The physician touches the filament to the patient’s sole with just enough pressure to bend, which is a force of 10 grams. Nerve damage is apparent if the individual cannot feel the strand of nylon.
  
  
• Ankle-brachial index (ABI). An easy-to-use, noninvasive office test that can indicate insufficient circulation. A blood pressure cuff on the arm is inflated until a handheld Doppler ultrasound device cannot detect a pulse in the brachial artery. The cuff is deflated until the Doppler device can detect a pulse (systolic pressure). The procedure is repeated on the leg, with the cuff on the lower calf. The Doppler is placed over the posterior tibial artery or dorsalis pedis, which gives the ankle’s systolic pressure. ABI is the ankle’s systolic pressure divided by brachial systolic pressure. A result of less than 0.8 is abnormal and indicates impaired blood flow in the legs.
  
  
• X-ray. Standard x-rays can reveal structural deformities, demineralization and possibly osteomyelitis (bone infection). The physician may order a bone scan, a type of radionuclide imaging, if osteomyelitis is suspected.

Scientists are refining technologies that can find early signs of diabetic foot ulcers and that may one day become standard tools for diagnosis. Medical hyperspectral imaging (MHSI) and magnetic spectroscopy are able to detect diabetic skin changes (reduced oxygen and diminished muscle energy reserves) before ulcerative foot disease develops. Development of these tools could identify at-risk individuals and help prevent ulcers.