Saturday, June 15, 2024
DIABETES Diabetic Infections

Gangrene and Diabetes: Causes & Treatment is a participant in the Amazon Services LLC Associates Program. As an Amazon Associate, I earn from qualifying purchases. Read full Disclosure here.

Diabetes can cause several foot problems. When there is long-standing hyperglycemia (elevated blood sugar levels), this can affect the sensation in your feet. This places you at higher risk for injury.

Not only that, elevated blood sugar levels can cause peripheral vascular disease. These factors can cause diabetics to develop foot gangrene. 

There are 3 types of gangrene.

  • Dry Gangrene
  • Wet Gangrene
  • Gas Gangrene 

In this article, you will learn about the different types of gangrene, what causes it, as well as treatment. 

What is Gangrene?

Gangrene is a serious condition that occurs when tissue dies in a certain area of the body due to a lack of blood supply.

 It can affect any part of the body, but typically starts in the extremities like the toes, feet, fingers, and hands. Gangrene is serious, and if left untreated, will become life-threatening.

Why Do Diabetics Get Gangrene?

People with diabetes are at an increased risk of developing gangrene, due to two major complications – peripheral vascular disease and neuropathy. 

The Health Effect of Blood Glucose Levels

Persistent hyperglycemia, or high blood sugar levels that require use of insulin, damages blood vessels. This impedes circulation and leads to tissue death. Also,  elevated blood sugar levels can lead to neuropathy, a nerve condition that reduces sensation in the feet, making it difficult for diabetics to detect early signs of foot injuries or infections. These untreated wounds can progress to gangrene.

Additionally, diabetes can suppress the immune system. This reduces the body’s ability to fight off infections, which can contribute to gangrene. 

Hence, diligent monitoring and proper foot care are crucial in preventing gangrene in diabetics.

What Are Other Risk Factors for Gangrene?

Other risk factors include arterial disease, smoking, obesity, and other chronic diseases that harm the circulatory system like Raynaud’s disease. 

Immunosuppressive conditions and advanced age can also increase the risk. Injuries or surgeries can potentially introduce bacteria that could lead to wet gangrene.

black lesions foot


Dry Gangrene

Dry gangrene is a condition resulting from inadequate blood supply to the foot tissues. This is often seen in people with diabetes because elevated blood sugar levels affect the blood vessels, leading to their narrowing and hardening. 

This, coupled with other risk factors like high cholesterol and smoking, heightens the risk of dry gangrene, particularly seen in the toes.

Symptoms of dry gangrene vary. Symptoms include intermittent claudication, which manifests as cramping pain in thighs, legs, and feet, especially during walking or even at rest, indicating severe vascular disease.

With restricted flow, feet can feel cold and skin may appear pale. Hair growth can be impacted, leading to slower growth or absence of hair in the toes. 

The affected area can experience swelling and pain, though some may not feel the pain due to neuropathy.

As the tissue dies, a change in skin color to purple or blue and eventually black is noticeable. The skin might also feel hard and shrunken. 

In severe cases, numbness and inability to move the foot leading to walking difficulties may be experienced.

Wet Gangrene

Wet gangrene is a form of gangrene that occurs when dry gangrene becomes infected, often spreading rapidly and posing a serious threat to the limb. It can also result from burns or frostbite injuries, necessitating prompt attention. 

Symptoms that someone with diabetes would see in the foot include skin discoloration transitioning from purple to blue and then black, pain, and a foul odor. 

Further indicators include blisters, pus, and fever, along with systemic symptoms such as lightheadedness, increased respiratory rate, and heart rate.

Gas Gangrene

Gas gangrene, like dry and wet gangrene, can affect diabetics due to injury and blood flow issues, but can rapidly become a life-threatening infection if untreated. 

It involves a bacterium called Clostridium perfringens, which produces toxins and gas in tissues leading to extensive tissue loss. 

Symptoms someone with diabetes would see in the foot include a presence of air in tissues, a crackling noise when the foot is pressed on, and skin discoloration varying from blue to purple, brown, and eventually black. 

Additional signs include a foul smell, blisters, and foot swelling. Systemic symptoms such as fevers, chills, nausea, and lightheadedness may also indicate this infection.


Foot gangrene is diagnosed through a series of clinical examinations and tests. During your routine foot visit, the physician will assess your foot, observing for discoloration, foul odor, or other signs of tissue damage indicative of gangrene. 

If gangrene is suspected, further tests may be required. These include blood tests to check for signs of infection, imaging studies like X-rays, MRIs, or ultrasounds to visualize tissue health, and possibly an arteriogram to evaluate blood flow in the affected area. 

In certain cases, a tissue or fluid sample may be taken for laboratory analysis to identify any infectious bacteria present.  

surgery instruments


Treatment for dry gangrene in the foot usually involves auto-amputation, where the gangrenous portion spontaneously falls off. This can take months, but provided there’s no infection and pain is managed, it’s an acceptable approach. 

Doctors will assess foot pulses to determine blood flow in the artery, possibly utilizing tests like Ankle Brachial Index (ABI) or an Arterial Duplex Ultrasound for more detailed insights.

If significant blockage is found, referral to a vascular surgeon may be necessary for interventions like stent or bypass surgeries. Keeping the gangrenous tissue clean and dry, potentially using antibiotics, is crucial. 

In extreme pain situations, surgical amputation might be performed, requiring a cast boot post-procedure.

Wet gangrene treatment demands an intensive approach. Doctors will examine the extent of tissue and bone damage using x-rays and MRIs, while also assessing arterial blood flow. 

Hospital admission for strong IV antibiotics is usually necessary. Surgery under anesthesia to amputate the necrotic tissue is critical to control infection. 

Tissue and bone samples may be obtained during surgery to identify the causative organism and guide antibiotic therapy. Post-operative care involves diligent wound care and potentially a period of non-weight bearing, especially after extensive amputations.

Gas gangrene requires immediate treatment with IV antibiotics and surgical removal of dead tissue. Doctors prioritize controlling the infection and salvaging as much of the foot as possible. 

Following surgery, daily wound care is essential, and the patient may need to remain non-weight bearing until healing is sufficient. Pain management will be crucial, particularly with potential phantom pain and sensation after amputation.

How Can Diabetics Prevent Gangrene?

It’s very important to visit your local foot doctor regularly if you have diabetes. If you are at high risk for developing gangrene due to numbness in your feet, you should see your foot doctor every 2-3 months. 

Your foot doctor will perform a diabetic foot exam and assess your blood flow. He/she will address any foot issues early on. 

Monitor Your Symptoms

It’s also important to pay attention to symptoms associated with poor blood flow, such as cramping in your feet. If you smoke, it’s important to try to quit smoking. 

It’s also important to follow a healthy diet to reduce the risk of high blood glucose levels. 

Make sure to check your feet daily for any cuts and bruises. Check your feet for skin changes. If you notice purple, red, blue, or black discoloration in your feet, call your doctor immediately. 

Gentle massages can help improve circulation in the legs. Make sure you are not wearing compression stockings if you have vascular disease. This can limit blood flow and cause pain. 

Avoid Barefoot Ambulation

If you have diabetes, avoid walking barefoot and make sure to wear protective diabetic socks and shoes. You cannot spread gangrene from person to person. 

doctor performs foot exam

When Should You See a Healthcare Provider for Foot Infections From Diabetes?

You should consult with a healthcare provider for foot infections from diabetes at the earliest sign of a problem, such as any unusual skin discoloration, cuts, bruises, or changes in sensation. 

Regular foot exams every 2-3 months by a Podiatrist are also recommended, especially if you’re at high risk due to numbness or vascular disease.


In summing up, medically reviewed studies and clinical observations highlight that individuals with diabetes are at an increased risk of gangrene, predominantly due to complications such as peripheral artery disease and neuropathy.

Regular, thorough foot examinations in a professional clinic setting can play a pivotal role in preventing the onset of gangrene, a condition that can progress swiftly with potential limb and life-threatening implications.

Effective non-surgical therapy methods, including proper foot care and blood glucose control, can enhance arterial blood flow and prevent exacerbation of peripheral artery disease. 

Therefore, timely intervention and continuous vigilance are integral to preventing severe outcomes associated with gangrene in diabetic patients.

Related article: Diabetic Neuropathy in the feet- A Simple Treatment Guide


gangrene pin


  1. Al Wahbi, A. (2018). Autoamputation of diabetic toe with dry gangrene: a myth or a fact?. Diabetes, metabolic syndrome and obesity: targets and therapy, 11, 255.
  2. Huang, Y. Y., Lin, C. W., Yang, H. M., Hung, S. Y., & Chen, I. W. (2018). Survival and associated risk factors in patients with diabetes and amputations caused by infectious foot gangrene. Journal of Foot and Ankle Research, 11(1), 1-7. 10.1186/s13047-017-0243-0
  3. McKittrick, L. S., McKittrick, J. B., & Risley, T. S. (1949). Transmetatarsal amputation for infection or gangrene in patients with diabetes mellitus. Annals of surgery, 130(4), 826.
  4. Mills, J. L. (2016). Lower limb ischaemia in patients with diabetic foot ulcers and gangrene: recognition, anatomic patterns and revascularization strategies. Diabetes/Metabolism Research and Reviews, 32, 239-245.
  5. Armstrong, D. G., & Lipsky, B. A. (2004). Diabetic foot infections: stepwise medical and surgical management. International wound journal, 1(2), 123-132.

DISCLAIMER: The information, including but not limited to, text, graphics, images and other material contained on this website are for informational purposes only. No material on this site is intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified healthcare provider with any questions you may have regarding a medical condition or treatment before undertaking a new health care regimen, and never disregard professional medical advice or delay in seeking it because of something you have read on this website.

Vaishnavi Bawa
Dr. Vaishnavi Bawa is a Podiatrist who specializes in treating foot and ankle pathology. LifesLittleSteps mission is to educate the public about foot health in an easy-to-understand manner using evidence-based medicine.
Posts created 129
Back To Top