An arterial ulcer, a venous leg ulcer and a diabetic foot ulcer may all look like a wound that refuses to heal, but the problem underneath can be very different.
An arterial ulcer develops when too little blood reaches the tissue. A venous ulcer develops when blood has difficulty returning from the leg and venous pressure remains high. A diabetic foot ulcer is more complicated because diabetes can cause nerve damage, pressure injury, infection and arterial disease, often in combination.
That is why I would not recommend deciding the treatment from a photograph alone. The wound needs to be examined, the arterial and venous circulation may need testing, and in diabetes we also need to assess sensation, pressure and infection.
Why Does the Type of Leg Ulcer Matter?
Because the correct treatment for one type of wound may be inappropriate for another.
For example, compression is an important part of treatment for many venous ulcers.
But if the same patient has severe arterial disease, strong compression may be unsafe unless the arterial circulation has first been properly assessed.
Likewise, repeated dressings may protect an arterial wound but will not correct a severe blockage preventing enough blood from reaching the foot.
A diabetic foot wound may need:
- pressure relief
- infection treatment
- arterial assessment
- wound care
- diabetes management
sometimes all at the same time.
So before asking:
“Which dressing should we use?”
I prefer to ask:
“Why did this wound develop, and what is preventing it from healing?”
Arterial vs Venous vs Diabetic Foot Ulcer: Quick Comparison
| Feature | Arterial Ulcer | Venous Ulcer | Diabetic Foot Ulcer |
| Main problem | Too little arterial blood reaching tissue | High venous pressure and poor venous return | Often neuropathy and pressure, sometimes combined with arterial disease and infection |
| Common location | Toes, foot, heel or pressure/distal areas | Lower leg, often around the ankle | Commonly pressure-bearing areas of the foot or toes |
| Surrounding skin | May appear cool, pale, thin or poorly perfused | Often swollen, pigmented, inflamed or hardened | May have callus, deformity, dry skin or signs of infection |
| Pain | Can be significant, especially with ischemia | Can ache or be uncomfortable | May be surprisingly painless if neuropathy is present |
| Foot pulses | May be weak or absent | Usually preserved if there is no arterial disease | May be normal or reduced depending on whether PAD is also present |
| Main circulation issue | Arterial | Venous | May be neuropathic, arterial, mixed or both |
| Common tests | Pulses, ABI, toe pressures, Doppler, arterial imaging | Venous duplex plus arterial assessment when needed | Neuropathy assessment plus arterial Doppler, ABI/TBI, toe pressures and wound/infection evaluation |
| Compression | Not automatically appropriate | Often important after suitable assessment | Depends on whether venous disease and arterial disease are present |
This table describes common patterns.
It is not a diagnostic checklist.
Real wounds can look different, and mixed disease is common.
What Is an Arterial Ulcer?
An arterial ulcer develops when the tissues are not receiving enough blood through the arteries.
One common cause is peripheral arterial disease, or PAD.
PAD develops when plaque builds up inside the arteries and narrows the channel through which blood reaches the leg and foot.
When circulation becomes severely reduced, the skin and deeper tissues may not receive enough oxygen to remain healthy or heal after injury.
A small wound can then remain open or become progressively worse.
For more information about the underlying artery disease, read the guide to peripheral arterial disease and blocked leg arteries.
Where Do Arterial Ulcers Usually Occur?
Arterial ulcers are often found on more distal parts of the limb, such as:
- toes
- tips of toes
- foot
- heel
- areas exposed to pressure or minor trauma
Current PAD guidance distinguishes ischemic arterial wounds from venous ulcers and neuropathic ulcers partly by their typical distribution and surrounding vascular findings.
But location does not prove the diagnosis.
A heel ulcer in a person with diabetes, for example, may involve:
- pressure
- neuropathy
- arterial disease
- infection
or several of these simultaneously.
What Other Signs Can Suggest an Arterial Ulcer?
Features that raise concern for poor arterial circulation include:
- a cold foot
- weak or absent foot pulses
- pale skin
- toe discolouration
- black tissue
- pain in the foot while resting
- pain that becomes worse when the leg is elevated
- walking-related calf pain
- slow wound healing
An arterial wound may appear relatively dry compared with a heavily draining venous wound.
However, wound appearance becomes less reliable when infection, diabetes or mixed disease is present.
Are Arterial Ulcers Always Painful?
No.
Severe ischemia can cause substantial pain, particularly pain at rest.
But diabetes can damage nerves.
A patient with neuropathy may therefore have a seriously ischemic wound without experiencing the amount of pain another person would feel.
That is an important safety point.
A painless diabetic foot wound is not automatically a minor wound.
Look at circulation, sensation, infection and tissue condition together.
What Is a Venous Leg Ulcer?
A venous ulcer develops because of persistently high pressure within the veins of the lower leg.
Veins normally carry blood back towards the heart.
Valves inside the veins help prevent blood from falling backwards.
When these valves stop functioning properly, or when a previous DVT damages or obstructs the venous system, blood can pool within the leg.
Over time this can cause:
- swelling
- heaviness
- inflammation
- brown pigmentation
- hardening of the skin
- eventually an open wound
Venous ulcers commonly occur in areas of chronic venous skin change on the lower leg, particularly around the ankle region. Current PAD guidance describes venous ulcers as typically occurring in the distal leg and often being wetter or more draining than ischemic lesions.
What Does the Skin Around a Venous Ulcer Look Like?
Patients may notice:
- ankle swelling
- brown or dark pigmentation
- itchy skin
- eczema
- hardening of the lower-leg skin
- visible varicose veins
- fluid leakage from the wound
The ulcer may have an irregular outline.
These clues are useful, but they do not replace vascular assessment.
A person can have chronic venous disease and peripheral arterial disease at the same time.
That combination changes treatment decisions.
Why Is Compression Used for Venous Ulcers?
Compression helps reduce venous pressure and supports blood returning upwards through the leg veins.
For suitable patients, it is a central part of venous-ulcer treatment.
But compression needs context.
If arterial blood flow is significantly reduced, compression may need to be modified or avoided depending on the severity of the arterial disease. Current lower-leg-ulcer guidance specifically recommends evaluating arterial circulation when PAD is suspected because compression strategies change when arterial blood supply is impaired.
That is why I would not advise someone with an undiagnosed open wound to simply buy the strongest compression stocking available.
First determine what kind of circulation problem is present.
What Is a Diabetic Foot Ulcer?
A diabetic foot ulcer is an open wound occurring in a person with diabetes, usually on the foot.
But this label does not tell us the whole mechanism.
A diabetic foot ulcer may develop because of:
Neuropathy
Diabetes can damage sensory nerves.
A patient may not feel:
- pressure
- friction
- a blister
- a small cut
- a shoe injury
They may continue walking on the injured area because it does not hurt.
Repeated pressure
Areas under the foot can experience repeated pressure during walking.
If sensation is reduced, this can lead to tissue breakdown.
Foot deformity
Changes in foot shape can concentrate pressure over particular areas.
Infection
Once the skin barrier breaks, bacteria can enter.
Infection can involve superficial tissues or spread deeper.
Peripheral arterial disease
Diabetes also increases the risk of arterial disease.
If circulation is poor, the wound has less oxygen and fewer nutrients available for healing.
Current diabetic-foot guidance recommends actively evaluating for PAD in a person with diabetes and a foot ulcer rather than assuming the wound is caused only by diabetic microvascular disease.
Is Every Diabetic Foot Ulcer an Arterial Ulcer?
No.
This distinction is very important.
Some diabetic foot ulcers are primarily neuropathic.
The arterial circulation may still be reasonably preserved.
Other diabetic wounds are ischemic, meaning poor arterial blood flow is an important part of the problem.
Many are neuroischemic, meaning both neuropathy and poor arterial circulation are present.
A wound can also become infected on top of either pattern.
“Diabetic ulcer” is not a third vascular category alongside arterial and venous.
It describes the patient context, while the actual wound mechanism still needs to be identified.
What Does a Neuropathic Diabetic Foot Ulcer Commonly Look Like?
Neuropathic ulcers commonly develop at pressure-bearing areas of the foot.
They may occur beneath:
- the forefoot
- metatarsal heads
- toes
- other areas exposed to repetitive pressure
Callus may surround the ulcer.
Current lower-extremity PAD guidance identifies pressure zones of the foot and surrounding hyperkeratosis or callus as common features of neuropathic ulcers.
Again, a typical appearance does not exclude arterial disease.
A diabetic patient can have neuropathy and PAD simultaneously.
Can Someone With Diabetes Have a Venous Ulcer?
Yes.
Having diabetes does not mean every leg wound is a diabetic neuropathic ulcer.
A person with diabetes can also have:
- chronic venous insufficiency
- varicose veins
- previous DVT
- venous hypertension
- a venous leg ulcer
Likewise, that same patient can also have arterial disease.
The diagnosis should therefore not stop at:
“The patient has diabetes.”
We still need to determine the vascular and mechanical causes of the wound.
Can an Ulcer Be Both Arterial and Venous?
Yes.
This is called mixed arterial and venous disease.
A patient may have:
- venous reflux causing swelling and high venous pressure
- peripheral arterial disease reducing blood reaching the foot
Both problems can contribute to poor healing.
This becomes particularly important when planning compression.
A venous-looking ulcer should not automatically receive high compression if arterial circulation is significantly impaired.
Testing helps establish how much each circulation problem is contributing.
Can You Tell the Type of Ulcer From a Photograph?
Sometimes the appearance provides useful clues.
But I would not use a photograph alone to make a final vascular diagnosis.
A photograph cannot reliably tell me:
- whether the foot pulses are present
- what the arterial pressure is
- whether venous reflux is present
- whether deep veins are obstructed
- whether neuropathy is present
- how deeply infection extends
- whether bone is involved
- whether a diabetic patient’s ankle arteries are calcified
Wound appearance is one part of assessment.
It is not the entire assessment.
Why Are Foot Pulses Checked?
Foot pulses provide a quick clinical indication of arterial blood flow.
The vascular examination commonly includes the arteries at the ankle and foot.
Weak or absent pulses increase suspicion of PAD.
But pulses alone do not answer every question.
This becomes particularly important in a diabetic foot wound, where more objective circulation measurements may be required.
What Is an ABI?
ABI stands for ankle-brachial index.
It compares blood pressure measured at the ankle with blood pressure in the arm.
It is widely used when PAD is suspected.
A reduced ABI can support the diagnosis of arterial disease.
But diabetes creates an important limitation.
Can ABI Be Misleading in Diabetes?
Yes.
Diabetes and kidney disease can cause arteries in the lower leg to become stiff and calcified.
These arteries may be difficult to compress when the pressure is measured.
The resulting ABI can appear higher or more reassuring than the true circulation would suggest.
Current diabetes guidance specifically advises careful interpretation of ABI in people with diabetes and notes that toe pressures can be more useful when arteries are non-compressible.
This is why I would not say:
“The ABI is normal, so circulation cannot be the problem.”
when the foot, wound and other vascular findings still suggest ischemia.
Why Are Toe Pressures Useful?
Toe arteries are often less affected by the type of calcification that makes ankle measurements difficult to interpret.
Toe pressure or a toe-brachial index can therefore provide additional information about blood reaching the foot.
Current international diabetic-foot PAD guidance recommends combining pedal Doppler waveforms with ABI and toe-brachial index rather than relying on one test alone.
In some cases, additional perfusion tests may also be useful.
When Is a Doppler Scan Needed?
Doppler ultrasound can help answer different questions depending on the wound.
Arterial Doppler
This assesses:
- arterial narrowing
- blockage
- blood-flow patterns
- areas of reduced circulation
Venous reflux Doppler
This assesses:
- faulty venous valves
- backward flow
- superficial venous reflux
- relevant deeper venous findings
These are not interchangeable scans.
The requested Doppler study should match the clinical question.
Dr Sravan’s Vascular Doppler Scan guide explains how different artery and vein studies are used.
Why Is My Wound Not Healing Even With Regular Dressings?
Dressings are important.
They can:
- protect the wound
- manage fluid
- protect surrounding skin
- support the wound environment
But they cannot independently correct every barrier to healing.
A wound may remain open because of:
- inadequate arterial blood supply
- untreated venous hypertension
- pressure
- infection
- neuropathy
- dead tissue
- repeated trauma
- uncontrolled swelling
- poor offloading
- smoking
- other medical problems
If a wound is not progressing despite regular care, the diagnosis and the circulation need reassessment.
Repeatedly changing the dressing brand is not always the answer.
Does Every Ulcer Need Antibiotics?
No.
Antibiotics are used when there is clinical infection.
An open wound can contain bacteria without necessarily requiring systemic antibiotics.
Signs that deserve medical assessment include:
- spreading redness
- increasing warmth
- swelling
- increasing pain
- pus
- fever
- worsening tissue
- foul discharge with other infection findings
- general illness
In a diabetic foot, infection can become serious, particularly when circulation is also poor.
Do not start or continue antibiotics indefinitely simply because a wound remains open.
The reason the wound is failing to heal still needs to be identified.
Why Can the Wrong Treatment Delay Healing?
Consider three examples.
Example 1: Treating an arterial ulcer with dressings only
The wound surface is repeatedly cleaned and covered, but severe arterial disease remains untreated.
The tissue continues receiving inadequate blood flow.
Example 2: Treating a venous ulcer without controlling venous pressure
Dressings manage the wound, but swelling and venous hypertension continue.
Healing can remain difficult.
Example 3: Treating a neuropathic plantar ulcer without offloading
The dressing is appropriate, but the patient continues placing repeated pressure on the same area with every step.
The wound repeatedly breaks down.
That is why wound treatment needs to address the mechanism.
What Treatment Does an Arterial Ulcer Need?
The first priority is understanding how much arterial circulation is reaching the foot.
Treatment may involve:
- cardiovascular risk-factor management
- prescribed medication
- wound care
- infection treatment
- protection from trauma
- revascularisation when ischemia is clinically significant
Revascularisation may involve angioplasty, stenting, bypass or another vascular strategy depending on the anatomy.
Not every arterial narrowing requires a procedure.
But when poor circulation is contributing to a non-healing wound or threatened tissue, restoration of blood flow may become an important part of treatment.
What Treatment Does a Venous Ulcer Need?
For a confirmed venous ulcer with adequate arterial circulation, treatment commonly includes:
- appropriate compression
- wound care
- swelling management
- movement and calf-muscle activity
- skin care
- evaluation of underlying venous reflux
Selected patients may also benefit from treatment of significant superficial venous reflux.
What Treatment Does a Diabetic Foot Ulcer Need?
The treatment depends on which problems are present.
A diabetic foot pathway may require:
- infection assessment
- wound cleaning and debridement
- pressure offloading
- neuropathy management
- arterial circulation assessment
- revascularisation when ischemia is important
- blood-glucose management
- footwear modification
- ongoing wound review
There is no single treatment called “diabetic foot treatment” that applies to every ulcer.
The diabetic foot care and treatment guide provides broader information about diabetic foot problems.
When Does a Non-Healing Wound Need More Urgent Evaluation?
Seek prompt medical assessment if a wound has:
- rapidly spreading redness
- increasing swelling
- pus or significant discharge
- fever
- rapidly worsening pain
- black or rapidly darkening tissue
- worsening depth
- exposed deeper structures
- significant surrounding infection
A diabetic foot wound deserves particularly timely review when infection or poor circulation is suspected.
When Is a Circulation Problem an Emergency?
Seek immediate hospital assessment if a foot suddenly becomes:
- very painful
- markedly cold
- pale or blue
- numb
- weak
- difficult to move
These symptoms can indicate an acute loss of arterial blood flow.
Do not wait for a routine Doppler appointment.
Likewise, sudden major one-sided leg swelling accompanied by chest pain, breathlessness, coughing blood or collapse requires emergency medical assessment.
When to See a Vascular Surgeon
A vascular surgeon becomes particularly relevant when a wound may be affected by poor arterial or venous circulation.
Consider vascular assessment if:
- a leg or foot ulcer is not healing
- foot pulses are weak or absent
- the foot is persistently cold
- there is toe discolouration
- a diabetic foot wound is not progressing
- there is significant leg swelling with an ankle wound
- venous skin pigmentation or hardening is present
- a venous ulcer repeatedly returns
- an arterial or venous Doppler is abnormal
- the cause of the ulcer remains unclear
- compression has been suggested but arterial circulation has not been assessed despite concern for PAD
Dr Sravan C.P.S is a vascular and endovascular surgeon in Bangalore whose clinical work includes peripheral arterial disease, chronic venous disease, diabetic foot circulation, non-healing wounds and vascular Doppler assessment.
Vascular assessment is not about attaching a label to the wound.
It is to identify the circulation problem that may be preventing healing.
Frequently Asked Questions
What is the main difference between an arterial and venous ulcer?
An arterial ulcer develops because insufficient arterial blood reaches the tissue. A venous ulcer develops because venous blood does not return efficiently and pressure remains high in the lower leg. Their treatment differs, so circulation assessment is important when the cause is uncertain.
Is every diabetic foot ulcer caused by poor blood circulation?
No. Many diabetic foot ulcers develop primarily because neuropathy reduces sensation and repeated pressure damages the skin. However, peripheral arterial disease is also common in people with diabetic foot ulcers and can significantly impair healing, so arterial circulation should be assessed when appropriate.
Can someone have both an arterial and venous ulcer?
A wound can occur in a leg with both arterial and venous disease. This is often described as mixed disease. Identifying both problems matters because severe arterial impairment can change how compression therapy is used.
Why is ABI checked before compression?
ABI provides information about arterial blood flow. When significant arterial disease is present, the compression plan may need to be modified. In diabetes, ABI can sometimes be misleading because calcified arteries may be difficult to compress, so Doppler waveforms and toe measurements may also be useful.
Can you identify an ulcer type by where it appears?
Location provides clues but cannot make the diagnosis by itself. Venous ulcers often occur around the lower leg and ankle, neuropathic ulcers commonly occur over pressure areas of the foot, and arterial wounds often affect distal foot or toe areas. Mixed disease and diabetes can change these patterns.
Why is my leg ulcer not healing even though the dressing is changed regularly?
The wound may have another barrier to healing, such as poor arterial blood flow, persistent venous pressure, infection, pressure, neuropathy or repeated trauma. Dressings manage the wound surface but cannot correct every underlying cause.
When should a non-healing ulcer be assessed by a vascular surgeon?
Vascular assessment is useful when arterial or venous disease may be contributing, particularly with weak pulses, a cold foot, significant swelling, venous skin changes, toe discolouration, diabetes, recurrent ulcers or a wound that is not improving despite appropriate treatment.
Conclusion
Arterial, venous and diabetic foot ulcers can all become chronic wounds, but they should not be treated as though they are the same condition.
An arterial ulcer raises the question of whether enough blood is reaching the tissue.
A venous ulcer raises the question of whether high venous pressure is preventing the lower leg from recovering.
A diabetic foot ulcer requires an even broader assessment because neuropathy, pressure, infection and peripheral arterial disease can occur together.
And some patients have mixed arterial and venous disease.
That is why the safest approach is not:
“What does this wound look like?”
but:
“What is causing this wound, how is the circulation, and what is stopping it from healing?”
A wound can tell us that there is a problem.
The vascular assessment helps tell us which problem needs to be treated.
