Diabetic foot ulcer

People with diabetes have an increased chance of developing foot problems such as foot ulcer. This is commonly known as 'diabetic foot'.

Key points

  1. A foot ulcer is a slow-healing open sore that develops on your foot.
  2. About 1 in 5 people with diabetes (20%) will develop a foot ulcer sometime during their life and about 50% of those ulcers will become infected.
  3. An infected diabetic ulcer is a serious problem.
  4. Foot ulcers occur most often on the ball of your foot or on the bottom of your big toe.
  5. Ask your doctor to examine your feet regularly for any sign of nerve damage or poor circulation.
  6. Foot problems can be avoided if you take care of your feet and act quickly if you have a problem.

What causes diabetic foot ulcer?

People with diabetes have an increased chance of developing foot ulcers because you are more likely than other people to damage the skin on your feet. This is because diabetes can cause nerve damage, so you don't notice if your foot is injured or sore. Diabetes also causes blood vessel damage so your skin can't heal easily.

What increases my risk of having diabetic foot problems? 

You are at low risk for diabetic foot problems if:

  • your blood-glucose levels are kept as low as possible
  • you look after your feet
  • you have feeling in your feet
  • your feet have a good blood supply
  • you don't smoke.

You are at medium or high risk for diabetic foot problems if:

  • you have lost some feeling in your feet
  • you have reduced circulation in your feet
  • you have hard skin on your feet
  • the shape of your feet has changed
  • diabetes is damaging your vision
  • you can't look after your feet yourself
  • you have had ulcers before
  • you have had an amputation.

What are the signs and symptoms of diabetic foot ulcers?

Foot ulcers are open sores or wounds that occur most often on the ball of your foot or on the bottom of your big toe. They may also develop on the side of your foot, usually because of poorly fitting shoes. The ulcers are usually painless. Not all diabetic foot ulcers become infected but people with diabetes are at high risk of developing infection of the ulcer and the surrounding skin (cellulitis). 

Depending on the severity of the wound and the presence of infection, diabetic foot ulcer can be classified in 4 ways:

  • Uninfected – the wound does not have signs of infection. 
  • Mild infection – the area around the wound may be warm to the touch, red, slightly swollen, painful or tender, and the wound may ooze pus.  
  • Moderate infection – foot infection that involves the deeper layers of your skin, into the muscle, tendons, bone or joints.
  • Severe infection – foot infection that causes sepsis (which is a life-threatening complication of infection). The symptoms of sepsis are high body temperature (fever), fast heartbeat, and heavy or quick breathing.  

What is the treatment for diabetic foot ulcer?

If you have diabetes and notice a sore or blister on your foot, contact your doctor immediately. Not treating ulcers can result in infection, which can cause loss of a limb. This can be avoided if you take care of your feet and act quickly if you have a problem.

Treatment of the foot ulcer depends on the severity of the wound. 




  • The wound is usually cleaned with saline wash and covered with a protective dressing.
  • Until the wound heals, rest the affected foot and do not put pressure on it by walking.
  • Walking on the ulcer can worsen it by making it larger and force infection deeper into your foot.    

Not infected

  • Your doctor may prescribe a waterproof dressing that can be applied and left in place for up to 1 week.

Mild infection

  • Your doctor may prescribe a non-sticky dressing that can be applied every 1–2 days.   

Moderate infection

  • Your doctor will prescribe a course of antibiotics.
  • Take your antibiotics as they have been prescribed and complete the course.

Severe infection

  •  You will be admitted to hospital. 

Lifestyle factors that improve wound healing

In addition to managing the wound, attention to other lifestyle factors can also contribute to improved wound healing.

  • Maintain good blood glucose control.
  • Treat high blood pressure and high cholesterol.
  • Stop smoking. 
  • Reduce weight with exercise and healthy diet.

How can diabetic foot ulcers be prevented?

Looking after your feet can help prevent foot ulcers and avoid serious complications. Good foot care includes checking your feet every day, keeping them clean and dry, wearing proper footwear and trying to avoid doing things that could damage them.

Get a foot check at every healthcare visit and seek urgent medical advice if you notice a cut, ulcer or other injury on your foot.

Learn more about diabetes and foot care.

What complications can foot ulcers cause?

If the foot ulcer does not heal, becomes worse or badly infected, or if the infection spreads to nearby bones or joints, this can lead to gangrene. The only solution then may be to surgically remove (amputate) the affected part.

What support is available for people with diabetic foot problems?

There are many groups and people keen to share their knowledge and tips for living well with diabetes.Diabetes NZ has branches around the country with awide range of services, resources, groups and shops. 

Regional diabetes support 

Learn more

The following links provide further information on diabetic foot ulcer. Be aware that websites from other countries may contain information that differs from New Zealand recommendations.

Diabetic foot ulcers DermNet NZ
Diabetes, foot care and foot ulcers Patient Info, UK
Diabetes and how to care for your feet Diabetes NZ 
The right steps to healthy feet Diabetes NZ 
Feet Diabetes NZ 
Diabetes and foot problems Diabetes UK 
How to look after your feet if you have diabetes NHS, UK


  1. Diabetic foot problems: prevention and management NICE Guideline, UK, 2015
  2. IWGDF guidance on the diagnosis and management of foot infections in persons with diabetes International Working Group on the Diabetic Foot (IWGDF), 2015
  3. International best practice guidelines: Wound management in diabetic foot ulcers Wounds International, 2013
  4. Diabetes and how to care for your feetDiabetes NZ
  5. The right steps to healthy feetDiabetes NZ
  6. FeetDiabetes NZ
  7. Diabetes and foot problemsDiabetes UK
  8. How to look after your feet if you have diabetesNHS, UK 

Reviewed by

Dr Jeremy Tuohy is an Obstetrician and Gynaecologist with a special interest in Maternal and Fetal Medicine. Jeremy has been a lecturer at the University of Otago, Clinical leader of Ultrasound and Maternal and Fetal Medicine at Capital and Coast DHB, and has practiced as a private obstetrician. He is currently completing his PhD in Obstetric Medicine at the Liggins Institute, University of Auckland.
Credits: Health Navigator Editorial Team. Reviewed By: Dr Jeremy Tuohy, Obstetrician & Researcher, University of Auckland. Last reviewed: 28 Feb 2020