HomeDiabetic Foot ResourcesDiabetic Foot Ulcer: Causes, Symptoms and Treatments

Diabetic Foot Ulcer: Causes, Symptoms and Treatments


People with diabetes are prone to foot ulcers due to complications with their circulatory and neurologic systems. It is the nature of diabetes to run interference with both of these functions, which means there are several causes and potential risks of a diabetic foot ulcer:

  • Neurological System Effects: Peripheral neuropathy is similar in sensation to the ‘fat flip’ experienced after an anaesthetic at the dentist’s office, and people with diabetes often suffer a similar loss of feeling in their feet and legs, meaning that they are not always aware of cuts or injuries that have occurred. A diabetic patient may believe that an ulcer “just appeared” when it had been festering for several days.
  • Neurological and Circulatory System Effects: Diabetic patients also often fail to register when too much pressure is applied to one area of the foot and may leave their limbs in a pressure-point situation that leads to ulceration. This failure of the body to shift positions, combined with a diminished circulatory system, means that ulcers are not only more likely to occur but will not heal as quickly due to a decrease in blood flow.

What is Diabetic Foot Ulcer?

When most people hear the word ‘ulcer,’ they often think of the illness associated with the stomach lining, but in reality, this is just one type of ulcer found in or on the body.

In simple terms, an ulcer involves layers of the skin breaking open and then not healing properly. Exterior skin ulcerations are usually accompanied by redness, swelling, and pain.

What Causes Diabetic Foot Ulcers?

Several factors contribute to the development of diabetic foot ulcers, including (but not limited to) impaired nervous system and circulatory system function:

  • Inability to feel pain in the foot and leg and thus unable to respond to the body’s distress signals.
  • Loss of protective reflexes: the sympathetic nervous system is often damaged and fails to communicate that pressure point friction or blood pooling has occurred.
  • Deformity of the foot structure: because diabetic patients don’t respond to pain stimuli, deformities of the foot can occur from abnormal positioning and lead to decreased circulation and blood flow, both of which contribute to the development of ulcers.
  • Connective tissue changes: changes in glucose levels can change connective tissue structure, leading to a host of complications, including a thickening of the sole pad, which may contribute to ulcer development.
    Poor foot care.
  • Improperly fitting shoes.

How To Take Care of Diabetic Foot Ulcer?

1. Check your feet every day! This is an absolute necessity. Have a friend or family member check your feet if you can’t reach your feet. If needed, put a mirror on the floor and put your foot over it to look for cuts, scrapes, bruises, openings, or areas of irritation.

check your feet every day

Make sure you check between your toes. Look for moist areas, white areas, or red areas.  Look for anything unusual. If you see something unusual, make an appointment with your podiatrist.

2. Don’t walk around barefoot. Needles, tacks, broken glass, and wood splinters can be hidden in the carpet, even if you vacuum regularly. You can puncture a foot without sensation. Punctures can go unnoticed and develop into ulceration or infections.

3. Watch out for folds in your socks. Rough seams and small folds in the socks can cause areas of irritation that may lead to skin breakdown and ulceration.

4. Don’t be a victim of fashion.  High fashion shoes usually lead to many problems on the feet. Make sure the shoes are wide enough. Don’t buy shoes that are too wide or too long which can cause a lot of slipping. Pick soft and flexible shoes and allow for cushioning on the top and sides but are rigid on the sole. Make sure they don’t fold in half.

Avoid high heel shoes.

You may be eligible for your insurance to pay for diabetic extra-depth shoes with custom insoles. These shoes will take the pressure off your feet and help prevent ulcerations. Ask your doctor. General information for picking out shoes.

5. Check your bath water with your hand before putting your foot in it. Your foot’s temperature is much different from the temperature your hand feels when you have neuropathy. Make sure to check the temperature with your wrist. This will be much more accurate than testing the water with your foot.

6. Avoid medicated corn pads. Medicated corn pads contain acid and can be dangerous to people with diabetes. Yes, it will remove the corn, but it is a good chance to remove all the surrounding skin. What you will be left with is ulceration. Check foot products you buy to ensure they are safe for people with diabetes.

7. Dry between your toes. Increased moisture between your toes can lead to the skin breaking down or foot fungus. This can eventually lead to an ulcer between the toes.  Ulcers between the toes go unnoticed for longer periods and can be difficult to treat.

8. Avoid cotton socks. Those white cotton socks we wear are not the right socks for a person with diabetes. Cotton socks don’t wick moisture properly. They lose their elasticity quickly and have a greater chance of thick seams and bunching at the toes. Try synthetic socks, acrylic, or small fiber wool socks. More information on socks.

9. Know your risk. Some people with diabetes do not have any loss of sensation or circulation in their feet. They are not at risk of developing ulceration and have a low risk of an infection becoming a problem. Others have severe neuropathy or circulation problems and don’t know it.

Doctor giving a patient foot treatment

It’s important to know your risk. Ensure your primary care doctor evaluates your feet and uses a monofilament wire (thin wire to assess sensation) or refers you to a podiatrist.

10. Do not trim your toenails, calluses, or corns. If you have a loss of sensation or blood supply, then have your podiatrist trim your corns, calluses, or toenails every two months.

Complications Associated with Diabetic Foot Ulcers

You must take special care for a diabetic patient to minimize the risk of ulcers forming, to begin with, as treating a patient with diabetes is much riskier than treating a patient without, for several reasons:

  • Once an initial ulcer develops, the patient is at increased risk for the condition becoming chronic. This is an undesirable situation because a multitude of ulcers can continue to develop, which is not only frustrating but extremely dangerous to the health of a diabetic patient.
  • If the initial ulcer deepens or grows worse, there is a serious increase in the risk of infection. When people with diabetes experience infection treating the affected area can be challenging, and if you cannot control it, it could lead to amputation.
  • The risk of amputation due to minor foot problems makes proper foot care just as critical to a diabetic’s health as correct and regular management of blood sugar and insulin levels.

Venous Ulcer

Venous ulcers occur in the leg, frequently above the ankle, and are caused by problems with the veins in the leg. It is also one of the most common types of ulcers that people with diabetes suffer from; it accounts for about 70% of all cases of ulcerations in patients with diabetes.

Venous ulcers are caused by poor functioning of superficial and deep level veins, which compromises blood flow and triggers the onset of ulcer development. This is not a difficult ulcer to diagnose as the skin becomes quite swollen, dry, itchy, and occasionally discolored. The ulcer will be suppurated and will likely show signs of eczema.

You can do several things to prevent a diabetic ulcer of this type:

  • Walk regularly; take the stairs when you can
  • Consume plenty of fresh fruits and vegetables
  • Decrease saturated fat in your diet
  • Maintain a healthy weight; lose weight if necessary
  • Do not cross your legs when seated
  • Frequently move around and change the position of your feet and legs if you don’t ‘feel the need’ because you may never feel it; it still needs to be done.
  • Wear support hose regularly
  • When seated, elevate your legs.
  • Inspect your feet and legs regularly. Check for open sores, redness, swelling, or brownish-colored skin. You cannot rely on pain indicators, so you must check manually for injuries and ulcers.

Arterial Ulcers

After Venous Ulcers, Arterial Ulcers are the second most common type of diabetic foot ulcer. While only 10% of ulcers are the Arterial kind, they can be much more painful and difficult to treat. While pain is not always a factor for diabetic patients, this in no way diminishes the risks posed by this type of sore.

If left untreated arterial diabetic foot ulcers can pose exceedingly dangerous risks to the patient’s health. The arteries are responsible for moving oxygenated and nutrient-rich blood from the heart to all other body areas. An arterial ulcer would interfere with this process, making quick identification and treatment of this particular ulcer crucial.

Arterial ulcers are most often found on the feet, particularly the heels, the ends of the toes, between the toes, and wherever the bones may protrude and create friction by rubbing against bed sheets, shoes, etc. These ulcers may also occur in the nail bed due to improper nail care.

A ‘punched-out’ appearance characterizes arterial diabetic foot ulcers, and the skin may be cool to the touch. The surrounding skin may have a waxy, pale, taught appearance when the leg is elevated; the entire foot may turn red when lowered.

The following steps can help reduce the risk of developing diabetic Arterial ulcers. They are the same suggestions for preventing venous ulcers, and they are important and effective enough to bear repeating:

  • Increase movement even when indoors
  • Be selective about the kind of shoes you wear.
  • Dry your feet properly after a shower or a foot soak. This eliminates any moisture that could mature into something else.


Diabetes will eventually cause the small blood vessels to become permanently damaged, and atherosclerosis (narrowing of the arteries) is always a risk with this disease. It has a devastating impact on the circulatory system.

Combined with a deterioration of the nervous system, atherosclerosis becomes one of the major causes and potential risks of a diabetic foot ulcer because it contributes to the problem and negatively interferes with the healing process.

Taking care of your general health, practising good foot and nail maintenance, and regularly inspecting your legs and feet for signs of injury or damage are three crucial steps that you must regularly undertake to reduce the risk of developing diabetic foot ulcers.

Dr Christine Nolan is the CEO and founder of Footdiagnosis.com. She also has extensive clinical experience and is therefore uniquely qualified to detect and manage diseases of the lower extremities including those related to peripheral arterial disease and diabetes.