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Diabetes and your feetGuide

Signs of wound infection

An infected wound usually shows two or more signs: pain, tenderness, warmth, redness, hardness or pus. A little redness can be normal healing. In people with diabetes, foot infections can become serious very quickly, so early care from a podiatrist matters.

Reviewed by Andrew Schox, BSc(Hons) PGradDipPod MPodLast reviewed 27 October 2026 6 min read

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  1. 1. What are the signs of a wound infection, and how common is it?
  2. 2. What can cause a wound to become infected?
  3. 3. How is a wound infection checked?
  4. 4. What can I do first?
  5. 5. What helps if that isn't enough?
  6. 6. Will it get better, and how do I stop it coming back?
  7. 7. When to see a podiatrist

At a glance

  • Two or more signs matter: in a diabetic foot wound, pain, tenderness, warmth, redness, hardness or pus together suggest infection.
  • Some redness is normal healing: a little redness, slight swelling and light-yellow discharge don't always mean infection.
  • A numb foot can hide it: poor feeling or circulation can make an infected wound look mild.
  • Early care matters: a podiatrist can clean the wound and take pressure off it, and antibiotics are kept for wounds with signs of infection.

What are the signs of a wound infection, and how common is it?

Infection is judged mainly by what you can see and feel. In a diabetic foot wound, that means at least two of these: pain, tenderness, warmth, redness, hardness around the wound, or pus. A wound with no pus and no signs of inflammation is counted as uninfected.

Healing wounds can look a bit angry too. Some redness, slight swelling and light-yellow discharge are normal and don't always mean infection. The signs aren't perfect: a wound can carry a lot of bacteria without showing them, so a mild-looking wound isn't automatically fine.

Infection is common: about 50% of diabetic foot ulcers become infected.

What can cause a wound to become infected?

Bacteria get in through a break in the skin. In people with diabetes, several things make that more likely. If your foot is numb, an injury can go unnoticed and the same spot may keep being damaged. Poor blood flow makes it harder for a sore to heal and fight infection, and together with numbness it can hide the signs of infection. Hard skin or dead tissue on an ulcer can also cause infection or slow healing.

Most infections involve more than one kind of bacteria, and staphylococci are the most common. Infection can spread to the bone, which is harder to diagnose and treat. If an infection isn't responding to treatment, the team may look for other causes, such as Charcot foot (a different foot condition).

How is a wound infection checked?

A podiatrist or doctor looks at the whole foot, not just the wound: the skin, the blood supply (including your foot pulses) and your sensation. Diagnosis rests mainly on the signs, not on tests alone.

If infection is suspected, a tissue sample may be taken after the wound is cleaned, ideally before antibiotics start. Infection is graded as mild, moderate or severe, which helps decide who needs hospital care, scans or surgery.

If bone infection is suspected, a plain X-ray usually comes first. An MRI is the most accurate scan, but a bone sample is still the most reliable way to confirm it.

What can I do first?

Until you're seen, cover the wound with a suitable dressing, keep it dry and take pressure off it, for example with footwear changes. It's best not to cut corns or calluses or use corn-removal products, as these can damage the skin and cause infection. A podiatrist can remove hard skin and dead tissue with a sterile blade, so the ulcer heals from the base upwards.

First-line treatment for a diabetic foot ulcer is removing dead tissue, taking weight-bearing pressure off the ulcer, and treating poor blood supply and infection. Antibiotics are for wounds with signs of soft tissue or bone infection; wounds without those signs don't need them. Your prescriber chooses the antibiotic and how long to take it.

What helps if that isn't enough?

Most diabetic foot infections need some surgery, from minor cleaning out of the wound (debridement) to bigger operations. Severe infection needs urgent drainage and removal of damaged tissue. A foot with poor blood supply may need a procedure to restore it.

If an infection isn't improving, the team may check for an undrained abscess (a pocket of pus), repeat the samples, and look again at pressure relief, wound care and circulation. Advice from infectious diseases doctors is recommended when infection isn't improving or keeps coming back. Foot care teams with several kinds of professionals improve outcomes.

Will it get better, and how do I stop it coming back?

A diabetic foot infection is serious, but treating it early lowers the risk of hospital stays and amputation. Delays in getting seen raise the risk of major amputation or death.

Checking your feet and acting early is the best habit to build. If you have a salon pedicure, bring your own nail tools to help prevent infection.

When to see a podiatrist

See your GP or a podiatrist the same day if:

  • you have diabetes and a new wound, sore, blister or colour change on your foot, or a callus with dried blood inside it;
  • a foot wound has spreading redness, heat, swelling or pus;
  • you have a fever, chills or feel generally unwell with a wound;
  • a foot infection turns black and smelly, which can mean gangrene;
  • you have an active foot ulcer, which needs urgent review.

For urgent advice when it isn't an emergency, call healthdirect on 1800 022 222 (24 hours a day), or go to a Medicare Urgent Care Clinic.

See a podiatrist or your GP if a cut, blister or bruise isn't starting to heal after a few days, even if it doesn't hurt.

Call 000 and ask for an ambulance if you have a foot wound or infection and develop confusion or slurred speech, severe shivering or extreme muscle pain, passing little or no urine, severe breathlessness, or skin that turns mottled, blue, grey, pale or discoloured. Don't wait for all of these to appear. Call too if a leg or foot suddenly turns cold and pale or blue, with pain or numbness, or can't be moved.

Go to the nearest emergency department if you have diabetes and a foot infection that's spreading fast, with a fever and feeling very unwell.

Most of this advice is about adults with diabetes. See your GP or a podiatrist the same day if a child or someone without diabetes has a wound with spreading redness, heat, swelling or pus.

Common questions

Can a wound be infected without pain, redness or swelling?

Yes. Poor circulation and loss of feeling can hide the usual signs, so an infected wound may look mild or feel painless. A numb foot can also let injuries go unnoticed. That's why checking your feet regularly matters, even when nothing hurts.

Does a wound swab tell me if it is infected?

Not on its own. Every open wound carries bacteria, so a positive swab is hard to interpret. Infection is judged mainly on the signs in and around the wound. A swab or tissue sample can help work out which bacteria are involved when infection is suspected.

Further reading

Want to know more? Signs of wound infection on Clindice

Reviewed by Andrew Schox, BSc(Hons) PGradDipPod MPod

Podiatrist

Reviewed 27 October 2026. Next review by 27 October 2027.

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GuideWound that won't healA wound that won't heal is one that has stalled instead of steadily improving, often because of vein or artery problems, diabetes or ongoing pressure. Care depends on the cause, so finding it comes first. A wound not improving after about 4 weeks, or any foot wound with diabetes, should be checked.GuideCharcot footCharcot foot is a condition in which nerve damage, usually from diabetes, weakens the bones and joints of the foot so they can break down and change shape. It often causes a warm, swollen foot with little pain. It needs prompt care from a diabetes foot team.

Sources

(14)
  1. 1.2012 Infectious Diseases Society of America clinical practice guideline for the diagnosis and treatment of diabetic foot infectionsLipsky BA, Berendt AR, Cornia PB et al. · Clinical Infectious Diseases · 2012
  2. 2.Diabetic foot infections (Guidelines)NHS
  3. 3.Wound or ulcer dressingsKent Community Health NHS Foundation Trust · 2024
  4. 4.Diagnostic Accuracy of Point-of-Care Fluorescence Imaging for the Detection of Bacterial Burden in Wounds: Results from the 350-Patient Fluorescence Imaging Assessment and Guidance TrialLe L, Baer M, Briggs P et al. · Advances in Wound Care · 2021
  5. 5.Diabetic Foot Ulcers: A ReviewArmstrong DG, Tan TW, Boulton AJM et al. · JAMA · 2023
  6. 6.Diabetes & Foot ProblemsNational Institute of Diabetes and Digestive and Kidney Diseases · 2026
  7. 7.Wound care adviceNHS
  8. 8.Evaluation and Management of Diabetes-related Foot InfectionsCortes-Penfield NW, Armstrong DG, Brennan MB et al. · Clinical Infectious Diseases · 2023
  9. 9.Gulf regional guidelines for managing diabetic foot ulcers: assessment, treatment and prevention of recurrenceJanahi N, Al Mahrizi AS, Ben Nakhi M et al. · Journal of Wound Care · 2026
  10. 10.Foot ulcerationNHS
  11. 11.Clinical practice recommendations for infectious disease management of diabetic foot infection (DFI) - 2023 SPILFBonnet E, Maulin L, Senneville E et al. · Infectious Diseases Now · 2024
  12. 12.Expert opinion on the management of infections in the diabetic footLipsky BA, Peters EJG, Senneville E et al. · Diabetes/metabolism Research and Reviews · 2012
  13. 13.Diabetic Foot Infection (Antimicrobial)NHS
  14. 14.Acute Diabetic Foot PathwayNHS

This page is general information, not a diagnosis or a treatment plan for you. For advice about your own feet or legs, see a podiatrist or your doctor. In an emergency, call 000.

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