Diabetic foot wounds, bone infection and infection after surgery
A wound that will not heal, a red and hot foot in diabetes, or a deep pain in a bone can be a sign of infection. This page explains what to show a doctor early, how infection is investigated, and why bone infection is treated for a long time.
What does this page cover?
Three closely related topics: foot wounds in diabetes, bone infection, and infection at the cut after an operation. What they share is that bacteria get from the skin or a wound into deeper tissue, and treatment has to reach that depth.
Diabetic foot wounds. The CDC says about half of people with diabetes have some nerve damage, mostly in the feet and legs. Feeling of touch and pain is reduced and a wound can stay painless. The CDC says poor blood flow also raises the risk of foot sores. An infected wound heals badly, and the CDC warns that if it does not respond to treatment, even amputation of a toe, foot or leg may be needed.
Bone infection (osteomyelitis). The NHS describes it as a painful infection in the bone that usually responds well to early treatment, but delay can lead to lasting bone damage. Germs reach the bone from a wound, fracture, surgery or foot ulcer. In diabetes, small cuts that are not felt can reach the bone.
Surgical site infection. The CDC describes it as an infection in the part of the body where the surgery took place, and says it may involve the skin, tissue, organs or an implanted device. The CDC lists the signs as redness and pain around the surgery site, cloudy fluid draining from the wound, and fever. Treatment is usually antibiotics and depends on the germ, and some patients also need another operation. The NHS also counts a surgical wound as a risk factor for cellulitis (skin infection).
Who should be seen?
- Anyone with diabetes who has a sore, blister, infected corn, or ingrown toenail on the foot. The CDC says do not wait for the next appointment for these.
- A foot that is red, hot or swollen, broken skin, discharge, or new pain with no clear reason. These are signs that an NHS podiatry service in the UK lists for urgent attention.
- Severe pain, swelling, redness and warmth over a bone, or a high fever with feeling very unwell. For a bone infection the NHS says to get an urgent doctor’s appointment. If you have had a bone infection before and the symptoms have returned, act early.
- A surgical wound that becomes redder and more painful, drains cloudy fluid, or comes with fever. The CDC says to contact your doctor immediately in this case.
- People with weakened immunity (chemotherapy, HIV), or a recent fracture or operation, whom the NHS places in the higher-risk group for bone infection.
How is it investigated?
Examination. The wound, its depth, the warmth and feeling of the foot, and the pulses are checked.
Blood tests. The NHS says blood tests may be requested for a bone infection.
Imaging. A plain X-ray, CT or MRI, depending on the site and depth. What is done in hospital is described by the NHS and includes taking a bone sample.
Culture. MedlinePlus says a wound is sampled with a swab, and for a deeper wound fluid may be drawn with a syringe or tissue removed. Where and how the sample is taken is the doctor’s decision. Before you go, see the samples and cultures guide.
What does treatment look like in general?
- Antibiotics. Chosen on the basis of the culture and antibiogram. For bone infection the NHS says usually 4 to 6 weeks, and up to 12 weeks for a severe infection, sometimes in hospital and sometimes at home. For simple cellulitis it gives about a week, with recovery in 7 to 10 days. Both sources say to finish the course even when you feel better. The length and the end of treatment are for your doctor to decide.
- Surgery. The NHS says it is sometimes needed to drain pus or remove damaged tissue or bone, and may be done more than once.
- Wound care. Dressings and local care are set by the doctor or nurse and are not replaced by home remedies.
- Controlling the underlying condition. In diabetes the CDC mentions keeping blood sugar near target, quitting smoking and staying active.
What can you do yourself?
- With diabetes, look at your feet every day, even if you feel nothing. The CDC says to use a mirror or ask someone to help you see the soles.
- Wash your feet in warm, not hot, water. Do not soak them, and dry them well. Do not put cream between the toes.
- Do not walk barefoot, even at home. Wear suitable shoes and check inside them for foreign objects.
- Cut toenails straight across. Do not remove corns and calluses yourself.
- Do not start, stop or change medicine on your own. Do not put home ointments or powders on a wound without asking.
- Ask your doctor about a tetanus vaccine too.
- Diabetes UK says everyone with diabetes should have a foot check once a year.
When to act urgently
Call 115 or go to the emergency department right now: a high fever or shivering, confusion, fast breathing or heartbeat, pale skin or purple patches, cold and sweaty skin. The NHS counts these as signs of life-threatening complications in cellulitis. Do not drive yourself, and bring your medicines. The full list is in the urgent signs.
The same day: a new wound or redness, warmth, swelling, discharge or a bad smell in a diabetic foot. For a new concern such as a cut or blister, Diabetes UK says to contact your doctor or foot-care team straight away. If you cannot reach them, go to a health centre or hospital emergency department the same day.
This page is for information only and does not replace an examination.
Frequently asked questions
If I have diabetes, should I treat a small foot wound myself?
It is better not to. The CDC says to show a blister, sore, or infected corn to a doctor early, and not to cut corns and calluses yourself. Diabetes can reduce feeling in the foot and a wound can stay painless, so look at your feet every day.
My foot doesn't hurt but it has turned red. Does it matter?
Yes. Diabetes UK says that if the skin around a blister is red, you should see a doctor, and that for any new cut or blister you should contact your doctor or foot-care team straight away. Damaged nerves may not show pain. No pain does not prove there is no infection.
Why is the antibiotic for a bone infection so long?
The NHS says it usually takes four to six weeks of medicine, and up to twelve weeks for a severe infection. The exact length is set by your doctor based on the type of germ and your response. Do not stop the medicine halfway on your own.
Will I need an operation?
Sometimes. The NHS says surgery may be needed to drain pus, relieve pressure, or remove damaged bone. Whether it is needed in your case becomes clear after an examination and imaging.
Which signs after an operation mean infection?
For cellulitis, the NHS says the skin becomes painful, hot and swollen, sometimes with flu-like symptoms, and that early treatment stops it getting worse. For a surgical site infection, the CDC lists redness and pain around the wound, cloudy fluid draining, and fever, and says to call your doctor straight away. Show any spreading redness, discharge, local warmth or fever after surgery to a doctor the same day.
The first step, a calm conversation.
Go to the booking page or talk to support. Either way, we are with you.