A diabetic foot exam is a standardized, non-invasive screening tool used by healthcare professionals to identify early signs of damage caused by diabetes in the feet. Diabetes compromises the body’s circulatory and nervous systems, making the feet vulnerable to injury, infection, and slow-healing wounds. This routine assessment detects subtle changes in sensation and circulation before they progress into severe complications, such as foot ulcers and lower-extremity amputation. The objective is to enable timely intervention and preventive care, maintaining long-term mobility and health.
The Purpose and Frequency of the Exam
The examination addresses the dual threat diabetes poses to the lower limbs: nerve damage and poor circulation. Loss of protective sensation (neuropathy) means minor injuries like blisters or cuts may go unnoticed because the pain signal is not transmitted. An unobserved wound is a potential entry point for serious infection.
The exam also screens for peripheral artery disease (PAD), where narrowed arteries reduce blood flow, slowing the body’s ability to heal and fight infection. When neuropathy is combined with poor blood flow, the risk of a wound progressing to a major complication rises. A comprehensive foot examination is recommended at least once a year for all individuals with diabetes, while those identified as high-risk require more frequent checks.
Components of the Diabetic Foot Exam
The comprehensive diabetic foot exam begins with a thorough visual inspection. The healthcare provider examines the skin for dryness, cracks, or color changes, and looks for early indicators of trouble like calluses, corns, or fissures between the toes. They also check for foot deformities, such as bunions or hammertoes, which create high-pressure areas and increase the risk of skin breakdown.
Neurological Assessment
The neurological assessment focuses on detecting the loss of protective sensation. This is typically done using the 10-gram Semmes-Weinstein monofilament test. The clinician applies the flexible nylon filament to specific points on the bottom of the foot, applying pressure until the filament bends, and the patient reports whether they feel the touch.
The inability to feel the monofilament indicates the patient has lost the ability to sense minor trauma, a major risk factor for ulceration. This test is supplemented by a vibration perception check, using a tuning fork placed against a bony prominence, such as the big toe joint, to assess larger nerve fiber function. The ankle reflex assessment, checking the Achilles tendon reflex, is another standard neurological check.
Vascular Assessment
A vascular assessment checks for adequate blood flow to the feet. This involves palpating the two main pulses: the dorsalis pedis pulse (on the top of the foot) and the posterior tibial pulse (behind the ankle bone). The pulses are characterized as present or absent, and their strength is noted.
The clinician may also check the capillary refill time, the speed at which color returns to the skin after pressure is applied to a toenail. Delayed color return suggests sluggish circulation, pointing to potential peripheral artery disease. If pulses are absent or weak, further testing, like an Ankle Brachial Index (ABI) measurement, may be recommended to quantify circulatory impairment.
Understanding the Results and Risk Categorization
The results from the visual, neurological, and vascular assessments are combined to assign the patient a specific risk category for developing a foot ulcer, which dictates the management plan. The International Working Group on the Diabetic Foot (IWGDF) defines these risk strata to guide follow-up and care. Patients with normal sensation and circulation are categorized as very low risk (Risk 0) and require only the annual comprehensive exam.
A patient classified as low risk (Risk 1) has either loss of protective sensation or peripheral artery disease, but no history of foot ulcers. These individuals require a foot exam every six to twelve months. The moderate risk category (Risk 2) includes those with a combination of risk factors, such as neuropathy alongside a foot deformity.
The highest risk level (Risk 3) is assigned to any patient who has a history of a foot ulcer or a lower-extremity amputation. Patients in the moderate and high-risk groups need more aggressive preventive care, including specialized, protective footwear and frequent follow-up exams.