What Is a Foot Ulcer? Causes, Symptoms, and Treatment

A foot ulcer is an open wound on the foot that fails to heal on its own, often penetrating through multiple skin layers and sometimes reaching tendons or bone. These wounds affect 1.6 million people in the U.S. each year and carry a lifetime risk exceeding 33% for people with diabetes. Left untreated, they can lead to serious infection, hospitalization, and amputation.

Key facts to know upfront:

Foot ulcers develop most often from peripheral neuropathy, poor circulation, or repeated mechanical pressure on the foot.
People with diabetes or peripheral artery disease (PAD) face the highest risk.
Neuropathic ulcers are frequently painless, meaning patients may not notice them until the wound is already deep.
Early treatment dramatically improves outcomes and reduces the risk of limb loss.

What causes foot ulcers and who is most at risk?

Foot ulcers rarely develop from a single cause. Most result from several overlapping problems working together over time.

Peripheral neuropathy is the leading driver, accounting for 60–70% of diabetic foot ulcers. When nerves lose function, patients stop feeling minor injuries. A blister from a tight shoe or a small cut from walking barefoot goes unnoticed, then worsens quietly over days or weeks.

Peripheral artery disease (PAD) contributes to roughly 50% of diabetic ulcers. Reduced blood flow means the skin and underlying tissue receive less oxygen, slowing or completely blocking the healing process. Atherosclerosis in the peroneal and tibial arteries is a common culprit, and diabetes, smoking, hypertension, and high cholesterol all accelerate its progression.

Other contributing factors include:

Foot deformities such as hammertoes, hallux valgus, Charcot foot, and equinus, which shift pressure onto vulnerable skin areas.
Ill-fitting footwear that creates friction or compression on bony prominences.
Poor glycemic control, which impairs immune response and tissue repair.
Trauma or repetitive pressure, particularly on the plantar surface during walking.
Autonomic neuropathy, which reduces sweat production, leaving skin dry and prone to cracking.

Pro Tip: Check your feet daily, including the soles and between the toes. Use a mirror or ask a family member to inspect areas you cannot easily see. Catching a small skin change early is far easier than treating a deep wound later.

How do you recognize the symptoms of a foot ulcer?

Foot ulcers often look like a round, red crater in the skin, sometimes surrounded by thickened, callused edges. Most appear on the bottom of the foot, the sides, or the tips and tops of the toes.

Common signs include:

An open wound or sore that does not close within a few weeks
Skin discoloration, ranging from red to dark or blackened tissue
Swelling, warmth, or redness around the wound
Drainage, odor, or visible tissue at the base of the sore
Burning, itching, or tingling near the affected area

One of the most dangerous aspects of neuropathic ulcers is that they are often completely painless. Patients with sensory neuropathy may walk on a deep wound for days without realizing it. By the time the ulcer becomes visible or causes swelling, infection may already be present.

Clinical note: Approximately 31–32% of hospitalized patients with diabetes and foot ulcers undergo lower extremity amputation. Delayed recognition is one of the most preventable contributors to that outcome.

If you have diabetes or circulation problems and notice any unusual skin change on your foot, treat it as urgent. Do not wait to see if it resolves on its own.

What are the different types of foot ulcers?

Clinicians classify foot ulcers into three main categories based on their underlying cause, and the type directly shapes how treatment is approached.

Neuropathic ulcers develop from nerve damage. They appear on pressure points such as the metatarsal heads or heel, present with punched-out edges surrounded by callus, and are typically painless. The patient’s foot often has normal pulses and good blood flow.
Ischemic ulcers result from PAD and poor blood supply. They tend to appear on the tips of the toes or the lateral borders of the foot, are usually painful, and the surrounding skin looks pale or dusky. Peripheral pulses are often absent or diminished.
Neuro-ischemic ulcers combine both neuropathy and arterial disease. They are more common in older patients with long-standing diabetes and multiple health conditions. Pain levels vary, and the ulcer’s location depends on which factor is more dominant.

Understanding the type matters because treating an ischemic ulcer without first restoring blood flow will not produce healing, regardless of how well the wound itself is managed.

How do doctors diagnose a foot ulcer?

Diagnosis starts with a thorough clinical examination. The clinician assesses the ulcer’s size, depth, location, and surrounding tissue, then classifies it using a validated system such as SINBAD (Site, Ischemia, Neuropathy, Bacterial infection, Area, Depth) to guide treatment decisions.

Key diagnostic steps include:

Neurological assessment using a 10-gram monofilament or tuning fork to detect sensory loss.
Vascular evaluation through ankle-brachial index (ABI) testing or Doppler ultrasound to measure blood flow.
Probe-to-bone test to check for underlying bone infection (osteomyelitis). A positive result strongly suggests bone involvement.
Blood tests including white cell count, CRP, and ESR, though normal inflammatory markers do not rule out deep infection.
Imaging with X-ray as a first step; MRI is the standard when osteomyelitis is suspected and X-ray findings are inconclusive.

The goal of this workup is to answer three questions: Is there bone infection? Is blood flow adequate for healing? Is there active soft tissue infection requiring urgent treatment?

How are foot ulcers treated?

Effective treatment addresses the wound itself and the underlying conditions driving it. The International Working Group on the Diabetic Foot (IWGDF) recommends a multidisciplinary approach that goes well beyond local wound care.

Core treatment strategies include:

Debridement: Removing dead or infected tissue is the foundation of wound care. Surgical or sharp debridement clears the wound bed and stimulates healing. This typically needs to be repeated at regular clinic visits.
Offloading: Reducing pressure on the ulcer is critical. Non-removable knee-high offloading devices produce the best outcomes because patients cannot remove them between appointments.
Infection control: Infected ulcers require antibiotics, chosen based on wound culture results. Severe infections may need intravenous therapy and hospitalization.
Vascular intervention: When PAD is present, restoring blood flow through angioplasty or bypass surgery is often necessary before the wound can close.
Wound dressings: Moist wound dressings protect the wound bed and support tissue regeneration. Proper dressing selection depends on wound depth, drainage level, and infection status. A good resource on post-operative wound care covers dressing principles that apply to many foot wounds.
Glycemic control: Keeping blood sugar in a healthy range supports immune function and tissue repair.

Pro Tip: The most common reason offloading fails in practice is that patients remove their devices at home. A non-removable total contact cast eliminates that problem entirely. If your doctor offers this option, take it seriously.

Expert clinical insights on managing foot ulcers

Any foot wound that has not improved within two to four weeks warrants professional evaluation. Waiting longer is one of the most common mistakes patients make, particularly when neuropathy masks pain.

“A non-healing foot ulcer is not just a skin problem. It is a marker of systemic disease requiring metabolic stabilization, vascular assessment, and aggressive infection control alongside wound management.” — IWGDF Guidelines 2023

Multidisciplinary teams produce measurably better outcomes than single-provider care. A complete team typically includes a podiatrist, an infectious disease specialist, and a vascular surgeon. The podiatrist manages wound care and offloading; the vascular specialist addresses blood flow; the infectious disease physician guides antibiotic selection for complex infections.

Post-healing vigilance is equally important. Recurrence rates reach 40% within one year and 65% within three years of wound closure. Structured foot self-care and monitoring after healing are not optional extras. They are the difference between a one-time event and a recurring cycle.

What happens if a foot ulcer goes untreated?

Untreated foot ulcers escalate quickly. Localized infection can spread to deeper tissues, reaching tendons, joints, and bone. Osteomyelitis (bone infection) is one of the most serious complications and often requires prolonged antibiotic therapy or surgical removal of infected bone.

Beyond the foot itself, severe infections can trigger sepsis, a life-threatening systemic response. Gangrene, the death of tissue from lack of blood supply, may develop when ischemia goes unaddressed. At that stage, amputation is often the only option to save the patient’s life. Post-amputation five-year mortality in patients with diabetes exceeds 50%, underscoring how serious these wounds become when ignored.

When should you see a doctor for a foot ulcer?

See a doctor immediately if you notice any of the following:

An open sore on your foot that has not healed within one to two weeks
Redness, warmth, or swelling spreading beyond the wound edges
Fever, chills, or feeling generally unwell alongside a foot wound
Foul odor or unusual discharge from the sore
Darkening or blackening of skin near the wound
Any foot wound if you have diabetes, PAD, or known neuropathy

You do not need to wait for pain. As noted above, many serious foot ulcers are painless. The absence of discomfort is not a sign that the wound is minor. For patients in Las Vegas seeking specialized evaluation, Stridefootankle offers comprehensive foot and ankle care with a focus on early intervention and personalized treatment.

How long does it take for a foot ulcer to heal?

Healing time varies widely depending on ulcer type, depth, blood supply, infection status, and how well underlying conditions are controlled. Shallow neuropathic ulcers with good circulation may close within six to twelve weeks with proper offloading and wound care. Deep or infected ulcers, or those complicated by PAD, can take months and may require surgical intervention.

Several factors slow healing: poor glycemic control, active infection, inadequate offloading, smoking, and insufficient blood flow. Conversely, early diagnosis, multidisciplinary care, and patient adherence to treatment consistently improve outcomes. Given that recurrence rates reach 65% within three years, healing the wound is only the first step. Long-term monitoring and foot numbness evaluation remain part of ongoing care.

Key Takeaways

Foot ulcers are serious wounds that require prompt, expert care to prevent infection, amputation, and long-term complications.

Point	Details
Prevalence and risk	Foot ulcers affect 1.6 million Americans each year; the lifetime risk exceeds 33% in people with diabetes.
Leading causes	Peripheral neuropathy accounts for the majority of diabetic ulcers; PAD contributes significantly.
Amputation risk	About 31–32% of hospitalized diabetic foot ulcer patients undergo lower extremity amputation.
Offloading is critical	Non-removable knee-high devices produce the best healing outcomes; removable devices are often not worn consistently.
Recurrence is common	Ulcers recur in 40% of cases within one year and up to 65% within three years of healing.

FAQ

What is the main cause of foot ulcers?

Peripheral neuropathy is the primary cause, responsible for most diabetic foot ulcers. It causes loss of protective sensation, allowing minor injuries to progress undetected into open wounds.

How do I tell if I have a foot ulcer?

Look for a round, open sore on the bottom, side, or toe area of your foot, often surrounded by thickened skin. Neuropathic ulcers may be painless, so any non-healing skin break warrants a clinical evaluation.

Will a foot ulcer ever heal?

Yes, most foot ulcers can heal with proper treatment including debridement, offloading, infection control, and managing blood sugar and circulation. Shallow ulcers with good blood flow may close within six to twelve weeks; deeper or infected wounds take longer.

How do I get rid of an ulcer on my foot?

Treatment requires professional wound care, not home remedies alone. A podiatrist will debride the wound, prescribe appropriate dressings, and address underlying causes such as poor circulation or uncontrolled diabetes to support healing.