A diabetic ulcer describes a slow-healing wound that commonly appears on the feet. It is a complication of diabetes that often stems from a lack of sensation or blood flow in the affected area. Without treatment and management, it can result in severe complications.

Diabetes is a condition that affects a person’s blood sugar levels due to how the body produces or uses the hormone insulin. Individuals with diabetes are unable to either efficiently use or produce sufficient insulin, leading to high sugar levels circulating in the blood.

Prolonged high blood sugar levels can damage blood vessels and nerves throughout the body. This can increase the risk of potential complications, such as developing slow-healing wounds known as ulcers. Without prompt treatment, these wounds can cause tissue death, which may result in amputation of a limb or death.

In this article, we will explore diabetic ulcers, including their causes, symptoms, and treatment.

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Diabetic ulcers are a potential complication of diabetes. They typically refer to an open sore or wound on the skin that cannot heal. A diabetic ulcer will often begin as minor trauma. However, due to a combination of factors, such as nerve damage and slow healing, a person may not notice the injury, and it may progress into an ulcer.

Around 15–25% of people with diabetes will develop diabetic foot ulcers. Without proper management, a diabetic ulcer can undergo necrosis and gangrene, which may require amputation.

There are three main types of diabetic ulcers:

  • Neuropathic: These wounds develop due to peripheral neuropathy, meaning a person loses sensation and cannot feel pain.
  • Ischemic: These injuries develop due to ischemia, which occurs when part of the body does not receive sufficient blood flow.
  • Neuroischemic: This refers to wounds developing from both neuropathy and ischemia.

Common causes of diabetic foot ulcers include:

  • high sugar levels
  • peripheral neuropathy
  • poor circulation
  • irritation or wounds occurring on the feet

Peripheral neuropathy describes damage to the peripheral nerves. These are the nerves outside the brain and spinal cord that relay information between the brain and the rest of the body. High blood sugar levels can damage these nerves, causing varying degrees of numbness, tingling, or burning in the extremities, such as the feet.

For example, a person may acquire an injury such as a blister but not notice it due to not feeling pain in their feet. This may result in the wound not being treated, causing it to worsen and develop into an ulcer.

Additionally, damage from high blood sugar levels can also increase the risk of conditions that affect the circulatory system, such as peripheral artery disease. These conditions can restrict blood flow and result in poor circulation, making the foot less able to heal and fight infections.

Other risk factors for diabetic ulcers may include:

Diabetic ulcers commonly affect the feet. They most often occur in the weight-bearing areas of the foot, such as the ball of the foot, heel, and tips of bent toes.

While most diabetic ulcers occur on the feet, they can also develop elsewhere on the body, including the legs, hands, and folds of skin on the stomach. For example, hand complications of diabetes are rare compared with foot complications, occurring in a ratio of 1:20.

Read more about diabetes and foot problems here.

An ulcer is an open wound, typically deep enough to see the underlying tissues, sometimes even the bone. A doctor will inspect the ulcer, noting its location, size, depth, and wound discharge.

This will include looking for signs of infection, such as:

  • swelling
  • hardening of the skin
  • redness around the lesion
  • local pain
  • presence of pus or drainage

The doctor will also try to identify the progression of ulceration and which factors may contribute to its development. Experts use different classifications of diabetic foot ulcers, with Wagner’s classification being one of the more common systems. It classifies ulcers as follows:

  • Grade 0: Skin intact, but the foot is at risk
  • Grade 1: Superficial ulcer
  • Grade 2: Deeper ulcer
  • Grade 3: Deeper tissue involvement, with abscess or osteomyelitis
  • Grade 4: Portion of the foot is gangrenous
  • Grade 5: Extensive gangrene involving the entire foot

After assessing the wound, they will also evaluate other functions, including:

  • motor and sensory function of the foot, including ankle reflexes, vibration, and light touch
  • foot shape, including changes in appearance and muscle wasting
  • skin status, including the presence of redness, sweating, or calluses
  • vascular status, including foot pulse, blood pressure, and Doppler waveforms

When someone identifies an ulcer, they should seek medical care to prevent its progression. The primary goal of treatment is to promote healing as soon as possible. Treatment will often depend on the grade of the ulcer.

If an infection is present, a doctor will likely prescribe antibiotics. They may require a tissue sample to identify the cause of the infection. The antibiotic type and dosage a doctor suggests will depend on the infection organism and the severity of the infection.

In some cases, surgical options may be necessary to help encourage healing, relieve pressure on the area, and prevent further complications. These options may include:

  • debridement (removal of damaged tissue)
  • skin grafts
  • vascular surgery
  • shaving or removing bones
  • reconstruction
  • realigning or fusing joints
  • lengthening tendons
  • amputation

Some other strategies that may help to manage diabetic ulcers include:

  • education on foot care and control of blood sugar levels
  • medications for blood sugar control
  • offloading pressure from the ulcer by using crutches, a wheelchair, or a non-removable cast to promote healing
  • medicines to help improve blood circulation
  • topical medications and dressings

The best treatment for diabetic ulcers is prevention. To help manage foot health, people should regularly check their feet and attend appointments with their podiatrist. Depending on certain risk factors, a doctor may recommend regular foot examinations every 1–6 months.

Tips to help prevent ulcers include:

  • keeping the feet clean, moisturized, and dry
  • wearing shoes that fit correctly
  • checking the skin daily for any blisters, cracks, cuts, ingrown toenails, and other minor injuries
  • keeping sugar levels within target ranges
  • not walking barefoot
  • seeing a podiatrist for any injuries
  • quitting smoking, if applicable

If someone notices any trauma to their feet or other concerning areas, they should contact a doctor and receive prompt treatment. Additionally, they should immediately seek medical attention if they see any signs of infection, including:

Diabetic ulcers are a common complication of diabetes. They refer to slow-healing wounds that often affect the feet. Without prompt treatment and management, they can result in severe complications. Prolonged levels of high blood sugar can damage blood vessels and nerves. This can impact sensation and blood flow in the extremities, which affects wound healing and can lead to the development of ulcers.

Although they are a common complication, diabetic ulcers are highly preventable. Managing blood sugars, proper foot care, and certain lifestyle changes, such as quitting smoking if applicable, can all help reduce the likelihood of diabetic ulcers.