Lower Limb Vascular Assessment
Reviewed by Andrew Schox, BSc(Hons) PGradDipPod MPod, October 2026
A lower limb vascular assessment checks how well blood is reaching your legs and feet. It is done mainly to find peripheral arterial disease (PAD), where the arteries in the legs are narrowed or blocked. It starts with questions, a look at your feet and a check of your pulses. Then it usually includes the ankle-brachial index (ABI), which compares the blood pressure in your ankle with your arm. The test is painless. The results show whether you need regular re-checks, more tests or a referral to a vascular service.
What is it?
A lower limb vascular assessment is a set of checks of the blood supply to your legs and feet. Its main purpose is to find peripheral arterial disease, often called PAD. This is when the arteries (the blood vessels that carry blood from your heart) in your legs become narrowed or blocked.
It starts with questions about your health and symptoms, then a look at and feel of your legs and feet. If more information is needed, it moves on to simple tests that don't involve needles or scans. The main one is the ankle-brachial index, or ABI. It compares the blood pressure in your ankle with the blood pressure in your arm.
Your podiatrist can do this assessment. It is also done by GPs, nurses, surgeons and other health professionals.
Why is it done?
PAD can reduce the blood reaching your feet. Blood carries the oxygen and nutrients your skin and tissues need to stay healthy and to heal. When the supply is low, sores heal slowly or not at all, and in serious cases tissue can be damaged.
About 1 in 2 people with diabetes who have a foot ulcer (an open sore) also have PAD. When PAD is present, the risk of problems with the leg and with the heart and blood vessels goes up. Finding PAD early lets your health team plan the right care.
PAD is also linked to a higher risk of heart attack and stroke. This is why the check matters even if you feel well.
Who needs it, and how often?
If you have diabetes. Everyone with a diabetes-related foot ulcer should have their circulation checked. The same goes for people with diabetes who are over 50, who have narrowed arteries elsewhere in the body, or who are Aboriginal or Torres Strait Islander people.
PAD in people with diabetes is often painless or has unusual symptoms. Nerve damage can hide the pain. So a lack of pain doesn't mean you can skip the check.
Your podiatrist places you in a foot risk category, from 0 (very low risk) to 3 (highest risk). This sets how often your feet are checked:
- Risk 0: once a year.
- Risk 1: every 6 to 12 months.
- Risk 2: every 3 to 6 months.
- Risk 3: every 1 to 3 months.
A foot ulcer that hasn't started to heal after 4 to 6 weeks of good care needs a closer look at the blood supply, whatever your usual schedule.
If you don't have diabetes. The check is usually prompted by symptoms. These include:
- leg pain when you walk that eases within a few minutes of rest
- numbness or weakness in your legs
- sores that don't heal
- constant foot pain, often worse at night
Smoking is the biggest risk factor for PAD. Diabetes, high blood pressure, high cholesterol and growing older also raise the risk. How often to re-check people outside diabetes isn't clear, so your doctor or a vascular service can advise you.
What happens?
Questions. Your podiatrist will ask about smoking, diabetes, blood pressure and cholesterol. They will ask whether walking brings on leg pain that eases with rest, whether you have pain at rest, and whether you have any sore below the knee that hasn't healed for more than 2 weeks.
A look at your legs and feet. They will check the colour and temperature of your skin. They will also look for changes such as thin or shiny skin, hair loss, thickened or misshapen toenails, sores or dead tissue. Cool or dry skin is common in PAD, but it can have other causes.
Feeling your pulses. Your podiatrist will feel for pulses in your groin, behind your knee, on the top of your foot and on the inside of your ankle. A weak or missing pulse is one clue that blood flow may be reduced.
Capillary refill and position tests. If your circulation is a concern, you may lie down while your podiatrist presses on a toe and watches how quickly the colour comes back. They may also raise your leg and then lower it to see how the colour changes. You'll usually be asked to lie down for this. Checking with your leg hanging down can wrongly make the circulation look better than it is.
The ankle-brachial index (ABI). A blood pressure cuff goes on your arm and on your ankle. A small ultrasound device picks up the blood flow. The two pressures are compared. The test is painless.
Extra tests if you have diabetes. The ABI can read falsely normal when the artery walls have gone stiff. This is more common with diabetes or kidney disease. Your podiatrist may also measure the blood pressure in your toe, which gives the toe-brachial index (TBI). They may use a handheld ultrasound device to listen to the blood flow in the arteries of your foot, and the pattern of the sound is called the waveform. Which tests you have depends on the equipment and training available.
What do the results mean?
Your podiatrist will read the results together with your pulses, your skin and any sores. One number is never read alone.
ABI below 0.9. This suggests reduced blood flow and makes PAD more likely.
ABI from 0.9 to 1.3. This is the usual range, and PAD is less likely. However, a result in this range doesn't rule out PAD if you have diabetes. If you have a sore that isn't healing, you still need further checks.
ABI above 1.3 or 1.4. The arteries are probably stiff or hardened, so the reading can't be trusted. This is common with diabetes or kidney disease, and in very old age. In this case your podiatrist will measure your toe pressure.
Toe-brachial index and toe pressure. A TBI below 0.7 is abnormal. A toe pressure below 30 mmHg usually goes with seriously reduced blood flow. A TBI of 0.75 or more is a reassuring result.
Foot waveforms. Smooth, wave-like patterns (called triphasic or biphasic) make PAD less likely. Flat or single-peaked patterns (monophasic) go with PAD.
Very low readings. An ABI below 0.5 suggests severely reduced blood flow and needs prompt referral. With a diabetes-related foot ulcer, urgent scans are considered if any of these are found:
- ankle pressure below 50 mmHg
- ABI below 0.5
- toe pressure below 30 mmHg
- TcPO2 below 25 mmHg (a skin test of oxygen in the tissue)
The exact cut-offs differ slightly between clinics and guidelines. For example, some use 0.9 as the lower end of normal and others use 1.0. Your podiatrist will use the ones their service follows.
What happens next?
Results in the usual range. You'll have your foot checks again on your usual schedule. If you have diabetes, this is set by your foot risk category. If an ulcer isn't healing or you have new symptoms, tell your podiatrist even if your last test was normal.
Signs of reduced blood flow. Your podiatrist may send you for more tests, such as an ultrasound or other scans, or refer you to a vascular service (doctors who specialise in blood vessels). Some referral pathways treat readings below 0.9 as routine referrals and readings below 0.5 as urgent.
Imaging. Scans have their own limits. A vascular specialist decides which suits you, especially if you have a contrast dye allergy, kidney problems, a pacemaker or claustrophobia.
If you have a foot sore. Take pressure off the area with footwear changes, temporary footwear or by putting less weight on that foot. Keep the sore dressed and dry until your podiatrist sees you. Getting help for warning signs should never wait for this.
Looking after your arteries. Stopping smoking, regular exercise and treating blood pressure, cholesterol and diabetes all lower the risk of heart and blood vessel problems if you have PAD. Check with your doctor or health professional before starting an exercise program if you have PAD or might have it.
When to see a podiatrist
Book an appointment if
Book an appointment with your podiatrist if you have diabetes and your foot check is due, or if you are over 50, Aboriginal or Torres Strait Islander, or have narrowed arteries elsewhere and haven't had your circulation checked. See your podiatrist or GP soon if you get leg pain when walking that eases within a few minutes of rest, numbness or weakness in your legs, or a sore on your leg or foot that keeps coming back or doesn't heal. Leg pain when walking is not just part of getting older.
Seek prompt assessment if
Call your local emergency number if your leg, foot or toes suddenly turn cold and pale or blue, with pain or numbness, or if you suddenly can't move your leg or foot. If you have a foot sore or ulcer and you also feel very unwell, with a fever, confusion or slurred speech, severe shivering or muscle pain, severe breathlessness, mottled or discoloured skin, or little or no urine, this could be sepsis: call your local emergency number. See your GP or another doctor today if you have constant foot pain that is worse at night, a sore that hasn't healed after more than 2 weeks, black or dead-looking skin on your foot, leg pain symptoms that came on quickly or have suddenly got worse, or a new foot ulcer with redness, swelling or warmth, especially if you have diabetes. If your GP can't see you today, go to an urgent care clinic or an after-hours GP.
Frequently asked questions
Is the ABI test painful?
No. It uses a blood pressure cuff on your arm and ankle, and a small ultrasound device to pick up the blood flow. You may feel the cuff squeeze for a short time, as with any blood pressure check.
Who can do a foot circulation check?
Many health professionals do it, including podiatrists, GPs, specialist nurses, physicians and surgeons. The tests you have depend on the equipment and training where you go. If a test can't be done there, you may be sent to a service that can do it.
Is leg pain when I walk just part of getting older?
No. Pain or cramping in the leg muscles that comes on with walking and eases within a few minutes of rest can be a sign of PAD. It's worth getting checked, because PAD also raises the risk of heart attack, stroke and loss of the limb.
What does it mean if my podiatrist can't feel a pulse in my foot?
It's a clue that blood flow may be reduced, but it isn't proof either way. Pulses can be hard to find in some healthy feet, and a pulse can be felt when there is still some disease. That's why your podiatrist also uses other checks, such as the ABI.