The Stages of a Diabetic Foot Ulcer: Progression and Complications

Foot ulcers are a common long-term complication of diabetes. And foot ulcers can be very serious. In early stages, diabetic foot ulcers can be successfully treated, giving you the best chances for a full recovery. But, in advanced stages, the risk of complications — like a foot or limb amputation — are high. 

Let’s take a closer look at the stages of diabetic foot ulcers and why it’s important to seek treatment early. 

What are diabetic foot ulcers?

Diabetic foot ulcers are open wounds that typically form on the plantar surface (bottom) of the foot. Diabetic ulcers may also appear on the leg as well. They can appear as small red, violet, or brown circular craters surrounded by thick, callused skin. They can occur when your blood glucose levels remain too high. Over time, this can damage the blood vessels and nerves in your feet, making foot ulcers more likely. 

What are the earliest signs of a foot ulcer in diabetes?

In order to detect the earliest signs of a diabetic foot ulcer, it’s important to check your feet daily. 

Warning signs to watch out for are:

• Swelling 

• Warmth or redness of the foot

• Skin discoloration

• Drainage or blood on your socks or in your shoes

• Foul-smelling odor from the foot

• Tenderness on a certain spot on your foot

If you have any of these symptoms, let a healthcare professional know right away. Catching these signs at the start can make healing faster and less complicated. 

Stages of a diabetes foot ulcer

Diabetic foot and leg ulcers are graded by their size, depth, location, and the area affected. They’re further categorized into stages that range from 1 to 6. Here’s a guide to help you know what to expect in each stage. 

Stage 1: A normal foot

At this stage, a healthcare professional will encourage you to wear well-fitting footwear and maintain proper foot care. 

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Stage 2: An at-risk foot

A healthcare professional will check to see if you have evidence of nerve damage or loss of blood flow due to diabetes. Both of these conditions put you at higher risk of foot ulcers. If you have any calluses, they should be removed by debridement. This is a procedure where a podiatrist (foot specialist) or other medical professional takes off thickened dead skin.

Stage 3: A foot with an ulcer

In this stage, you’ll likely need to decrease the pressure applied to your foot. This may be done using an air cast, wheelchair, or bed rest. Proper wound care is important to prevent infection in this stage. 

Stage 4: An infected foot

This stage may require hospitalization. An open wound should be tested with a culture. This is where a sample of fluid, skin, or tissue is taken to identify the bacteria or fungus present. This helps in finding the best antibiotic to treat the infection. A surgical procedure may be needed to drain and cut away infected tissue so the infection can be controlled.

Stage 5: A foot with some gangrene

This stage is when you have dead tissue due to infection or lack of blood flow. This is called gangrene. Treatment for this stage usually involves hospital admission, intravenous (IV) antibiotics, and bed rest. Depending on the wound, you may also need surgical treatment to help clear away infected and dead tissue.

Stage 6: A foot that needs amputation

At this stage, the damage from infection is so severe that the foot needs to be removed. You also have to be mindful because the immobility after surgery can result in a pressure ulcer on the remaining foot. You may need to use a special mattress, wedge pillow, or a schedule to move your foot often to help prevent ulcers from forming.

How quickly do diabetes foot ulcers progress?

The sooner a diabetic foot ulcer is treated, the better your outcome can be. A small blister can become a large ulcer in a matter of days. That’s why taking a look at your feet daily is important, especially if your diabetes is hard to manage. 

When your blood sugars remain high for too long, you may have a loss of sensation in your feet. As a result, an ulcer can go unnoticed for some time, and it may delay your treatment.

When should you seek treatment for diabetes foot ulcers?

If you have diabetes, you should seek medical care as soon as you notice any changes with your feet. Let a healthcare professional know if you think you may be developing the signs of a foot ulcer. 

If you already have a diabetic foot or leg ulcer, you’ll need to watch for signs of worsening. Let your healthcare team know if you begin to show any signs of infection, including:

• Increased redness or discoloration 

• Fever 

• Draining pus

It’s better to talk with a healthcare professional and be safe than to risk developing an ulcer, a severe infection, or an amputation.

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Written by:

Bernadette Anderson, MD, MPH

A native of Saginaw, Michigan, Dr. Bernadette earned an undergraduate degree in psychology from the University of Michigan, Ann Arbor. She completed a master's degree in public health at the University of California, Berkeley, and a doctorate of medicine from the Medical College of Ohio.

Edited by:

Karla Robinson, MD

Karla Robinson, MD, is a medical editor for GoodRx. She is a licensed, board-certified family physician with almost 20 years of experience in health through varied clinical, administrative, and educational roles.

Reviewed by:

Maria Robinson, MD, MBA

Maria Robinson, MD, MBA, is a board-certified dermatologist and dermatopathologist who has practiced dermatology and dermatopathology for over 10 years across private practice, academic, and telehealth settings. She is a fellow of the American Academy of Dermatology and the American Society of Dermatopathology.

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