A physician will likely conduct a physical examination and obtain a medical history, including a list of symptoms. Diagnosis methods will differ depending on which underlying condition is suspected of causing the foot problem:

• Peripheral neuropathy. To test for nerve damage, a physician can check the patient’s feet with a tool called a Semmes-Weinstein monofilament. The physician will apply pressure to the feet with these small nylon filaments, and the patient’s ability to feel this pressure will reveal the extent of damage. This test can offer good insight into a patient’s ability to feel injuries that may occur. People with diabetes are advised to receive the test yearly, or more often if advised by the physician. A thorough check of circulation in the feet should also be performed.
  
  Several other tests may be administered to determine the extent of nerve or muscle damage due to the peripheral neuropathy. These include:
  
  
• • Nerve conduction velocity studies. Small electrodes are placed on the arms and legs and an electric current is sent into the nerve. A slow or weak response to the current indicates nerve damage in that area.
    
    
  • Electromyography (EMG). Small, thin needles are inserted into muscles and responses are recorded on an EMG machine.
    
    
  • Quantitative sensory testing. Various hot, cold and vibrating stimulations are placed on the body to measure sensation.
    
    
  • Nerve biopsy or skin biopsy. A sample of nerve or skin tissue is examined to help identify nerve degeneration from neuropathy and confirm specific conditions.
    
    
• Charcot foot. This condition can be diagnosed based on its appearance and x-rays of the foot, which may reveal bone, joint or ligament damage.
  
  
• Peripheral arterial disease. Specially designed blood pressure cuffs can be placed at the thigh, calf, ankle, forefoot and toe to measure the blood flow in those areas. Some physicians may also perform an arteriography, a diagnostic procedure in which dye is injected into the arteries and x-rays and other analysis is used to look for blockages.

Recent research indicates that two innovative tests can find diabetic foot conditions early. Medical hyperspectral imaging (MHSI) and magnetic spectroscopy can detect low oxygen levels in the skin and reduced energy reserves in the foot muscles. If these tests become more available, they may reduce the rate of amputations, according to the researchers.