Peripheral vascular and diabetic foot examination

• A peripheral vascular and diabetic foot examination answers four questions: are the legs well perfused, are the veins competent, is protective sensation intact, and what is the patient's risk of a foot ulcer or amputation?
• The setting and order matter almost as much as the signs. Warm the room, expose both legs fully, and examine with the patient both supine and standing, because veins distend when upright and pulses are easier to feel when the leg is relaxed.
• Perfusion is judged from colour, temperature, capillary refill, the femoral, popliteal, dorsalis pedis and posterior tibial pulses, and the ankle-brachial pressure index (ABI). Its stages run from a normal index down to critical limb-threatening ischaemia.
• Venous disease is judged from varicose veins and their filling behaviour, pitting oedema, skin change around the medial malleolus and shallow ulcers that do not reach the deep fascia.
• Neuropathy is judged from a 10 g monofilament and a 128 Hz tuning fork, and turns a person with diabetes into a moderate, high or active risk category that dictates review interval and referral. ^[3][7]
• The examination is incomplete until the findings are classified and presented, including the negatives that change the differential such as a normal ABI or intact sensation.

By the end of this page you should be able to:

1. Prepare and introduce a peripheral vascular and diabetic foot examination and position the patient correctly.
2. Perform the inspection, pulse palpation, temperature, capillary refill, ABI, Buerger test, varicose vein, oedema and neuropathy steps in a fixed order.
3. Recognise the normal and abnormal signs of the skin, pulses, ulcers and sensation of the lower limb.
4. Calculate and interpret an ABI, including its limits in diabetes.
5. Classify a person's diabetic foot risk using the standard categories.
6. Present the same set of findings aloud and in the notes, with the most important finding first.

This page teaches the lower-limb vascular and diabetic foot examination as one continuous sequence rather than a set of isolated signs. Most students can list the pulses; fewer can keep the order, say what each step is testing, and turn a bedside record into a short verbal report. Both are examined, and both matter in practice, because a cool, pulseless foot and a risk-stratified diabetic foot are common reasons for same-day referral.

The examination has three parts that overlap. The vascular part asks whether blood is reaching the foot, whether the leg veins are leaking, and whether there is a reversible cause of skin damage. The neurological part asks whether protective sensation is preserved. The risk part asks how likely this person is to develop an ulcer or lose a limb over the coming months. You are not diagnosing peripheral arterial disease from one sign; you are building a picture from many. ^[6]

The setting is a warm, well-lit room and a couch that can be raised to about 45 degrees and lowered flat. You need a tape measure and ruler, a handheld Doppler probe of suitable frequency with ultrasound gel, a sphygmomanometer with cuffs of several sizes, a 10 g monofilament, a 128 Hz tuning fork, a watch with a second hand, hand gel and gloves, and a chaperone. Both legs must be visible from the groin to the toes, with the shoes, socks, bandages and dressings removed. For venous assessment the patient must stand at some point, because varices collapse when the legs are horizontal. ^[3]

Introduce yourself, confirm the patient's identity, explain the examination in plain words ("I am going to look at and feel the circulation and sensation in your feet and legs, and check for varicose veins; this will involve some gentle pressure and a cool metal tuning fork"), and obtain permission. Warn the patient that standing may be needed, and that the examination can stop at any time.

Obtain consent for both the examination and a chaperone. Offer a chaperone to every patient, regardless of sex, and use one whenever the examiner and patient are of different sexes if that is local policy. Document the chaperone's name or "offered and declined".

Clean your hands and the equipment before and after. Check the sphygmomanometer and Doppler probe before relying on them; a cuff with a faulty valve or a probe at the wrong frequency will mislead more neatly than any error of judgement. Calibrate your 10 g monofilament before use, since it bends at 10 g and fatigued filaments over-read.

Expose both legs from the groin to the toes with the patient covered and warmed elsewhere. Keep the patient supine and comfortable for the arterial and neurological parts, then standing for the venous part. Work on the patient's right side, and compare sides at every step: asymmetry is often the only thing that separates disease from normal variation.

Measure the resting heart rate, blood pressure in both arms, respiratory rate, temperature and oxygen saturation if they are not already recorded. An oxygen saturation below 95% is hypoxaemia and should be noted. ^[1] Systemic variables influence the leg examination: a cold, vasoconstricted patient has slower capillary refill in both feet, and a febrile, septic patient may have hot, oedematous feet with a normal or increased rather than reduced perfusion.

Do the same order every time. The sequence below moves from the general inspection inward, tests perfusion, then venous competence, then oedema, ulcers and sensation. Variation is allowed only when a step is impossible, for example in a patient who cannot stand.

Look first, before touching. Note cyanosis of the feet or toes, cachexia, distress, the patient's footwear (pressure areas and ill-fitting shoes), walking aids and any chronically bandaged limb. Count the respiratory rate yourself and weigh the patient if possible. Measure blood pressure in both arms at the brachial artery, because the higher arm reading is the denominator for the ABI.

Inspect from the groin to the toes with the patient supine, then repeat with the patient standing for the venous part. Record:

• Skin colour. Pallor on elevation and dependent rubor (a reddish or violaceous colour when the leg hangs down) suggest arterial insufficiency. Persistent redness around the medial malleolus with brown pigmentation suggests chronic venous change.
• Hair and nails. Loss of hair on the toes and shin, thickened brittle nails and atrophic, shiny skin accompany chronic ischaemia; fungal change is common and must be separated from it.
• Scars and marks. Note amputation scars, graft scars, injection sites and pressure areas.
• Callus and deformity. In a person with diabetes, callus over pressure points, claw toes, hallux valgus, pes cavus and Charcot deformity mark the foot at risk. ^[3]
• Varicose veins. Dilated, tortuous, bulging superficial veins at least 3 mm in diameter. ^[4] Inspect with the patient standing and feel for tenderness or hardness that would suggest thrombophlebitis.
• Oedema. Look as well as feel: ankle swelling, shin swelling and fullness of the dorsum of the foot.

Use the dorsum (back) of your hand and compare symmetrical points moving from the groin to the toes: thigh, calf, ankle, dorsum of the foot and toes. A foot that is cool relative to the other side or to the calf is an ischaemic sign. ^[6] Use warmth as a clue too: a warm foot with bounding pulses and a neuropathic ulcer suggests a different, high-risk perfusion state.

Press the nail bed or the plantar pulp of the great toe firmly for about 5 seconds, release, and count the seconds until colour returns. Do this on both feet and compare. In normal skin a refill time greater than 5 seconds is abnormal in this lower-limb vascular context; general perfusion assessment commonly treats a refill longer than 2 to 3 seconds as abnormal. ^[6] Capillary refill is a useful quick screen at the bedside, but it is affected by temperature, lighting and the pressure you apply, so a doubtful result should be confirmed with pulses and an ABI.

Palpate the pulses in a fixed order, comparing sides:

1. Femoral pulse, below the inguinal ligament, midway between the anterior superior iliac spine and the pubic symphysis.
2. Popliteal pulse, with the knee slightly flexed and the leg relaxed, pressing deeply into the popliteal fossa.
3. Dorsalis pedis pulse, lateral to the extensor hallucis longus tendon on the dorsum of the foot.
4. Posterior tibial pulse, behind and below the medial malleolus.

If you have not already done so, feel the brachial and radial pulses. Note whether each pulse is present, reduced or absent, and whether the two sides match. Delayed or absent femoral pulses with a radio-femoral delay point to coarctation of the aorta rather than simple peripheral arterial disease. Palpate the femoral pulses and then compare with the radial by feeling both at once. ^[1]

A comprehensive lower-limb pulse examination is the single most useful bedside perfusion test. Absence or reduction of any palpable pulse has a likelihood ratio of 4.7 for peripheral arterial disease, and no palpable pulse abnormality makes moderate to severe disease much less likely. ^[6]

Measure when perfusion is in doubt, or in every person with diabetes and a foot problem. The NICE (CG147) method is: ^[2]

• The patient rests supine if possible.
• Record the systolic blood pressure with an appropriately sized cuff in both arms and in the posterior tibial, dorsalis pedis and, where possible, peroneal arteries. ^[2]
• Take the measurements manually with a Doppler probe of suitable frequency in preference to an automated device. ^[2]
• Document the character of the Doppler ultrasound signals in the foot arteries.
• Calculate the index for each leg by dividing the highest ankle pressure by the highest arm pressure.

Interpretation, combining the two commonly used framings: ^{[1] [6]} Ranges differ between sources: the calcification cut-off is described as above 1.30 by some manuals and as above 1.40 by the PAD guidelines used here; some texts give normal as 1.0 to 1.3 and 'acceptable' as 0.90 to 0.99.

• Greater than 1.40: a high index, usually meaning non-compressible, calcified vessels (some manuals use greater than 1.30); the result is unreliable and should not be accepted as normal. ^[1]
• 1.00 to 1.40: normal by the PAD guidelines used here (some texts give 1.0 to 1.3).
• 0.91 to 0.99: borderline by the PAD guidelines used here (some texts label 0.90 to 0.99 acceptable).
• 0.90 or less: abnormal and likely significant narrowing; severity is often graded mild 0.71 to 0.90, moderate 0.41 to 0.70, severe 0.40 or less (grade bands also vary by source). ^[1]
• Lower values indicate more severe disease: intermittent claudication is usually seen with an index between 0.41 and 0.90; rest pain suggests severe ischaemia, often at or below 0.40; chronic limb-threatening ischaemia is defined clinically by rest pain or tissue loss and is commonly associated with an index below 0.40. ^[6]

Two cautions. First, an ABI that falls by more than about a fifth after exercise points to masked arterial disease even when the resting index is normal. ^[6] Second, in diabetes (and in end-stage renal disease and medial arterial calcification) the vessels may be stiff and non-compressible, so a normal or raised ABI can occur despite severe obstruction. Do not exclude peripheral arterial disease in a person with diabetes on a normal or raised ABI alone, and do not use pulse oximetry to diagnose it. ^[2] In diabetes, the ABI is an adjunct to the pulse and to Doppler waveform inspection, not a replacement.

With the patient supine, raise both legs and compare colour. Lower them and watch how quickly the feet regain their colour and normal warmth, and how quickly the veins refill; delayed colour return and dependent rubor suggest arterial insufficiency, while delayed refilling of the surface veins accompanies insufficiency of similar severity. ^[6] This is the same manoeuvre family as the venous filling time (below), so write down exactly what you saw rather than a grade. Firm pressure to the plantar aspect of the great toe for 5 seconds gives an abnormal capillary refill time above 5 seconds in normal skin. ^[6]

Inspect with the patient standing. Then test for reflux:

• Empty the veins by elevating the leg, apply a tourniquet or firm manual compression over the superficial veins at the saphenofemoral junction, and ask the patient to stand. ^[4]
• If the varicose veins fill while the tourniquet is still on, the reflux is coming from below (deep or perforator incompetence). If they fill only after the tourniquet is released, the superficial system is incompetent. ^[4]
• A venous filling time (leg raised 45 degrees for about a minute, then with the legs dangling) greater than 20 seconds is abnormal. ^{[6] [4]}

Varicose veins measure at least 3 mm in diameter when they are true varices. ^[4] Note their distribution (great and small saphenous territories), any tenderness suggesting superficial thrombophlebitis, and any ankle skin change.

Press firmly for several seconds over the shin, ankle, dorsum of the foot and, in bed-bound patients, the sacrum. Note whether the indentation persists (pitting), how far it reaches (ankle only, to mid-calf, to the knee), and whether it is symmetrical. Pitting oedema is graded 1 to 4, but the grades have no agreed definition, so describe what you saw rather than quoting a grade. ^[1] In chronic venous insufficiency the oedema is usually pitting and worsens with standing through the day, starting in the perimalleolar area. ^[4] Bilateral pitting ankle swelling with a raised jugular venous pressure points to fluid overload or heart failure; unilateral warm swelling suggests cellulitis or thrombophlebitis. ^[1]

Measure and document the size, depth and position of an ulcer. ^[3] Note whether the floor is granular or necrotic, the edges are sloping or punched out, the depth reaches tendon or bone, the exudate is serous or purulent, and the surrounding skin shows cellulitis, callus or maceration. Use a standardised system such as SINBAD or the University of Texas classification; do not use the Wagner classification, which NICE advises against. ^[3]

The combination of site and character usually separates the three common types:

• Venous stasis ulcer: usually around the medial malleolus, shallow, moist, often malodorous, sometimes painful, with the other signs of chronic venous change. It does not penetrate the deep fascia. ^[5]
• Arterial (ischaemic) ulcer: over the tips of the toes, the lateral malleolus, metatarsal heads or bony prominences, with a pale or necrotic base, punched-out edges and little granulation. The foot is cool and the capillary refill is prolonged. ^[6]
• Neuropathic ulcer: under a callus on the plantar surface at a pressure point such as the metatarsal heads or heel, in a person whose foot is warm (or even hot), often unnoticed by the patient and classically painless until infection occurs. ^{[3] [7]}

Patients rarely fit only one category, and a "mixed" arterial and venous leg ulcer is common in older people.

Test protective sensation in both feet, working proximally from the toes:

• Touch and pressure. Use a single-use 10 g monofilament. Apply it at a right angle to the skin until it buckles, at standard plantar sites, especially the distal plantar aspect of the great toe and the plantar side of the first or second metatarsal, and ask the patient whether it is felt. Loss at one or more sites is abnormal. ^{[3] [7]}
• Vibration. Place a 128 Hz tuning fork marked (d) on the interphalangeal joint of the great toe (and on the dorsum of the finger for comparison) and ask when it stops buzzing; abnormality is graded against 5 out of 8 or 6 out of 8 depending on age. ^[7]
• Pinprick, temperature and proprioception. Test proximal to distal, light versus sharp pinprick, warm and cool, and movement at the interphalangeal joint. Perform the ankle jerk (Achilles) reflex, which is often lost early and symmetrically. ^[7]
• Autonomic evidence. Look for dry, cracked skin and loss of sweating, which suggest sympathetic denervation and predispose to fissures. ^[7]

In a person with diabetes, on the basis of the examination, classify the risk of a future foot problem as: ^[3]

• Low risk: no risk factors other than callus alone. ^[3]
• Moderate risk: deformity, or neuropathy, or peripheral arterial disease on its own.
• High risk: previous ulceration or amputation; renal replacement therapy; neuropathy combined with peripheral arterial disease; or neuropathy, or peripheral arterial disease, combined with callus or deformity.
• Active diabetic foot problem: ulceration, infection, chronic limb-threatening ischaemia, gangrene, or suspicion of an acute Charcot arthropathy (an unexplained hot, swollen foot with a change in colour, with or without pain). ^[3]

In addition, any person with an active foot problem needs escalation as an emergency, including suspected osteomyelitis (limb ischaemia, deep soft-tissue or bone infection, gangrene, or sepsis) using the NICE (NG19) red flags. ^[3] People with diabetes should have a foot risk assessment when diabetes is diagnosed and at least annually thereafter. NICE advises reassessment every 3 to 6 months for people at moderate risk, every 1 to 2 months for those at high risk with no immediate concern, and every 1 to 2 weeks for those at high risk with immediate concern. ^{[3] [7]}

The table collects the signs you are most likely to have to elicit and to name. "How to elicit" is the practical action; "what it means" is the inference.

A presentation has four parts in this order: the headline, the system findings, the negatives that matter, and the summary with a differential. Hold the whole vascular and foot examination to about one minute, because the listener is matching it to the neurological and back examinations.

1. Headline. Start with the single most important finding, or say "the vascular and foot examination is normal". Lead with the limb at risk or the active ulcer, not with the pulses you counted.
2. System findings. Go in the order examined: general look and vitals; skin and temperature; capillary refill; pulses and ABI; varicose and oedema findings; ulcers; sensory loss and reflexes; diabetic foot risk category. State numbers: ABI, capillary refill seconds, oedema height, monofilament sites lost.
3. Negatives that matter. State only the findings that change the differential: pulses present, no radio-femoral delay, normal ABI, intact 10 g monofilament, no ulcer, no oedema, no rest pain. Do not list every normal finding; silence reads as normal.
4. Summary and differential. End with one sentence naming what you think and the main alternative, and one sentence on the next step: "In summary, this is a high-risk diabetic foot with an active plantar neuropathic ulcer and intact perfusion; I would arrange same-day multidisciplinary foot service review, offloading and wound care."

Matching written notes. Write short lines in the same order as the spoken presentation, one finding per line, with numbers: "Skin: warm left foot, cool right foot. CRT 6 s right, under 2 s left. Femoral and popliteal pulses present both sides, right dorsalis pedis and posterior tibial absent. ABI right 0.42, left 1.05. Right lateral malleolus ulcer 1.2 x 0.8 cm, punched-out base. Sensation: 10 g filament absent over right great toe, vibration 3/8 right, absent left?" Avoid prose, and do not add a diagnosis the findings do not support.

Presenting a diabetic foot. The lead is usually the risk category, then perfusion, then neuropathy: "This is a high-risk diabetic foot with absent protective sensation on the right; perfusion is intact with an ABI of 1.05, but there is a 1 cm plantar ulcer beneath a callus."

Presenting peripheral arterial disease. Put the level of disease and its severity before the ABI: "The right foot is cool, capillary refill is 6 seconds, the dorsalis pedis and posterior tibial pulses are absent, and the ABI is 0.42; the femoral and popliteal pulses are present, so the disease is below the knee."

Leading with the most important finding. Decide the lead by what determines management, not by what you found first. An active ulcer in diabetes leads with the ulcer and the risk category; in suspected critical ischaemia, the cool pulseless foot leads.

All patient details below are invented and illustrative; they are not real patients.

Normal examination, 46-year-old man, pre-operative assessment. "On examination both legs look well perfused. The skin is warm and pink to the toes, hair distribution is normal, and there is no cyanosis. Capillary refill is brisk in both feet. The femoral, popliteal, dorsalis pedis and posterior tibial pulses are present and symmetrical. The ankle-brachial pressure index is 1.12 on the right and 1.08 on the left. There are no varicose veins and no oedema. There is no ulcer, callus or deformity. Sensation to a 10 g monofilament and vibration at 8 out of 8 is intact bilaterally, and the ankle jerks are present. In summary, the peripheral vascular and diabetic foot examination is normal."

Arterial (ischaemic) foot, 69-year-old woman, rest pain. "On examination the right foot is cold and pale with elevation pallor and dependent rubor; the left foot is warm and pink. Capillary refill is 6 seconds on the right and under 2 seconds on the left. The right femoral and popliteal pulses are present, but the dorsalis pedis and posterior tibial pulses are absent; all pulses are present on the left. The right ankle-brachial pressure index is 0.42 and the left is 1.05. There is no oedema and no varicose vein. There is a 1.0 by 0.6 cm punched-out ulcer with a pale base over the lateral malleolus on the right and a small necrotic area on the second toe, with no surrounding cellulitis. Sensation is otherwise intact. In summary, the findings are consistent with right-sided below-knee peripheral arterial disease with critical limb-threatening ischaemia; alternatives to exclude include vasculitis, embolism and an acute thrombosis on chronic disease, and the patient needs urgent vascular assessment." ^[2]

Chronic venous insufficiency, 62-year-old man, swollen leg. "On examination there are bilateral great saphenous varicose veins and bilateral, asymmetrical oedema that pits to the mid-calf on the left and the ankle on the right, worse after standing. The skin around the medial malleoli is pigmented, indurated and eczematous, with lipodermatosclerosis on the left. Capillary refill is brisk. The femoral, popliteal and foot pulses are present and symmetrical, and the ankle-brachial pressure index is 1.08 on the left and 1.10 on the right. There is a 2.5 by 1.5 cm shallow, moist, mildly malodorous ulcer superior to the left medial malleolus, with sloping edges and a granular base; it does not reach the deep fascia. Sensation is intact. In summary, this is chronic venous insufficiency with an active venous stasis ulcer, but perfusion is preserved, so compression therapy can be considered under specialist guidance."

Diabetic neuropathic foot, 57-year-old man, type 2 diabetes. "On examination the right foot is warm and dry, with a thick plantar callus over the first metatarsal head and a 0.8 by 0.6 cm painless, deep ulcer at its base; the left foot is normal. There is mild clawing of the right toes. Capillary refill is brisk in both feet. The femoral, popliteal, dorsalis pedis and posterior tibial pulses are all present, and the right ankle-brachial pressure index is 1.15. The 10 g monofilament is not felt at three plantar sites on the right but is felt on the left; vibration sense is reduced to 4 out of 8 on the right and 8 out of 8 on the left; the right ankle jerk is absent. There is no oedema, no gangrene and no sign of osteomyelitis. In summary, this is a high-risk diabetic foot with a plantar neuropathic ulcer and intact perfusion, needing same-day multidisciplinary foot service review, offloading and wound care."

• Calling a leg warm because the room is warm. Always compare side to side and with your own hand; symmetry matters more than absolute temperature.
• Taking capillary refill alone as perfusion. Temperature, colour, pulses and the ABI must agree before you reassure or refer.
• Accepting a normal ABI in a person with diabetes as proof of normal perfusion. Calcified arteries give a falsely high index; check the Doppler waveforms and the pulses. ^[3]
• Measuring the ABI with an automated cuff or without the patient supine. The manual Doppler method is the standard and other readings are not comparable.
• Examining veins with the patient lying down. Varices and oedema that are obvious standing can be missed in bed.
• Describing oedema as a grade without saying what you saw. "Pits for 3 seconds to mid-calf" is interpretable; "grade 2 oedema" is not.
• Forgetting the monofilament because the pulses feel normal. A well-perfused foot can still be a high-risk neuropathic foot.
• Calling every foot ulcer "diabetic" or "venous" without defining site, depth and character. Description first, diagnosis second.
• Not stating the diabetic foot risk category. The category, not the list of signs, determines the review interval and referral.
• Reporting "no ulcer found" while missing the plantar surface. Remove the shoe, sock and callus inspection every time.
• Omitting the Buerger and ankle reflex parts of a vascular work-up. They take under a minute and change the differential.
• Listing every normal finding in the presentation. The listener loses the abnormal ones by the fifth item; lead with the abnormal.