Foot Complications
Diabetes can put a person at risk for developing a wide range of conditions. Often this is due to a combination of factors that are attributed to diabetes, including a loss of sensory, motor and autonomic nerve damage (neuropathy), poor blood supply to organs (ischemia) and foot deformity. However, keeping blood glucose as close to the target range as possible, managing blood pressure and cholesterol, healthy lifestyle modifications (getting regular physical activity, eating healthy, stopping smoking, drinking alcohol in moderation, getting regular sleep and managing stress) and following preventative foot-care recommendations (e.g., having an annual foot exam, looking at the bottom of the feet and lower legs each day to make sure there are no sores, cuts, or any objects in the foot, daily moisturization, etc.), can help prevent and/or delay the progression of serious foot complications.
Facts
- The lifetime risk for a foot ulcer in people with diabetes is 25 percent.1
- The rate of amputation is 15 times greater in people with diabetes than without diabetes.2,3
- About 50 percent of people with diabetes will eventually develop peripheral neuropathy.6,7
Foot ulcers
Often people do not realize they have a cut or wound on their foot because they cannot feel it (due to neuropathy), they often also have poor blood circulation slowing healing, as well as high blood glucose, so a trauma or wound in the foot often progresses before it is recognized. Over 80 percent of lower limb amputations occur after a foot ulcer. Both foot ulcers and amputation are associated with other complications such as retinopathy, nephropathy, peripheral neuropathy with loss of protective sensation (LPOS), peripheral artery disease (PAD), foot deformities, cigarette smoking, calluses and previous history of ulcers or amputation. They are also both associated with high mortality rates but are actually preventable (tips for prevention are in the Prevention section below).4,5
If there is a wound to the foot and it has progressed to an infection, the area can become red, hot, swollen and painful if the person can feel the area. If the infection has further progressed systemically fever, chills, sweaty/clammy skin, increased heart rate/low blood pressure and confusion or disorientation can occur. If there is neuropathy an infection will not be noticed until it has progressed (unless feet are examined daily). Therefore, it is imperative to conduct daily visual exams of the feet and legs for signs of infection/sores so it can be treated early.4,8,13,14
Treatment includes an oral and/or topical antibiotic. In addition, the doctor will clean the infected area and remove any dead or infected skin through a sterile procedure to help the wound heal. If the infection is at a more advanced stage, it may require hospitalization, IV medications and sometimes treatments (e.g., hyperbaric oxygen therapy) and/or skin grafts to close the wound are used as well as surgery. It is very important during this time to keep blood glucose as close to the target range as possible to promote healing and not put any pressure (e.g., weight) on the wound (known as offloading), so crutches, casts, or wheelchair may be needed depending on the area of the infection.4,8,13,14
Peripheral Neuropathy
Diabetic peripheral neuropathy (DPN) can include any disorder of the peripheral nervous system but is most commonly seen in the hands and feet. It begins in the furthest body parts from the center of the body (e.g., toes) and then progresses toward the body. It is one of the most common and expensive complications of diabetes. It is associated with chronic high blood glucose and cardiovascular risk factors. It appears that the tiny blood vessels are damaged and changes in the nerves occur similar to diabetic retinopathy and nephropathy. Intensively managing blood glucose has been shown to stop progression and/or improve symptoms of neuropathy.
Initially symptoms can include pain, burning (shooting pain) and tingling. Pain is often worse at night in the feet and anything touching the area affected by neuropathy is especially painful (e.g., socks or sheets when they touch the feet). People also lose the sensation of hot/cold or touch and can experience weakness and a numbing sensation. People with peripheral neuropathy experience an increase in falling and injuries because their balance is affected by the lack of feeling and muscle weakness. In addition, they may not notice if they have a cut or sore on their foot/legs because they do not feel it, which can progress into a more serious issue if not treated early.8
John McAuliffe, who was diagnosed with type 2 diabetes almost 20 years ago shares, “Neuropathy sucks—was diagnosed with type 2 because I had a sore on my foot (so I already had neuropathy when I was diagnosed). I am not steady on my feet and can’t feel anything below my knees. As I am getting older, I am weaker on my feet and can’t stand long. I did what the doctors told me but often my A1c would be high and then they would add another medication. It wasn’t until I got a cut on my foot that almost took my foot and life that I got a wake-up call. I have lost 60 pounds and my A1c has been in the 6s ever since. Take care of yourself is my advice.”
Diagnosis
It is also recommended for diabetes care providers to screen for diabetic neuropathy at diagnosis of type 2 diabetes, after five years of type 1 diabetes diagnosis, and then annually for both thereafter. Initially, screening is conducted via questions by the doctor, then with a monofilament and/or tuning fork and sometimes pinprick to evaluate sensation. Ankle reflexes and temperature sensation may also be evaluated. Additional tests may be conducted to assess the neuropathy including blood tests to rule out other causes of the symptoms and nerve conduction studies.8
Treatment
Treatment includes intensively managing diabetes, weight loss if overweight or obese, eating healthy, getting regular physical activity, drinking alcohol in moderation and stopping smoking. In addition, for painful neuropathy, medications will be prescribed. Depending on symptoms and their impact on the quality of life (e.g., disrupting sleep, interrupting daily activities) and having mental health conditions (such as anxiety or depression) will also be addressed. People are usually asked to monitor their symptoms to assess treatment effectiveness. It is also recommended to visually inspect the skin of the area that is affected by neuropathy to make sure there are no wounds.8
Drop Foot
Drop foot or foot drop can be caused by several issues, a key main contributing cause is diabetes complications. In drop foot, there is a gait or walking issue in which the front of the foot does not lift when walking, so the person drags their foot on the floor. Often the person may lift their foot with their thigh in a stomping motion to compensate when walking. Falling can be an issue if drop foot isn’t addressed, especially when walking stairs. It isn’t a disease but the result of an underlying neurological and/or muscular issue.
Drop foot is evaluated by health history and physical exam. In addition, imaging and nerve tests may be conducted. Treatment usually includes braces or splits to help hold the foot in a normal position and sometimes physical therapy. There are also adjustments around the house that can be made to avoid tripping and falling (e.g., avoiding area rugs, moving cords out of the way, etc.).
Skin Issues
Autonomic neuropathy (please refer to the autonomic neuropathy section) that affects the lower limbs can reduce sweating, cause dry skin and development of skin cracks. Motor neuropathy that affects the muscles in the foot can cause foot deformity. The foot deformity plus sensory neuropathy can cause high foot pressure forming calluses. Having a callus on the plantar area (bottom) of the foot increases the person’s risk of developing an ulcer.8,13
Fungal infections on the foot/between the toes (e.g., athlete’s foot) and nail infections (called onychomycosis in which nails have a yellow/brown/white discoloration and are thick and cracked) are also common in a person with diabetes. They are usually due to a combination of factors including medications, excess moisture and hyperglycemia. Treatment includes topical and oral antifungal medications. In addition, keeping blood glucose as close to the target range as possible and having good general hygiene (washing with soap and water, and thoroughly drying skin, etc.) can help prevent and treat the infection.13,14
Diabetes healthcare providers should conduct annual foot exams on all people with diabetes (if not more often) to evaluate if there are any signs of issues. Removal of the plantar callus is associated with a reduced risk of foot ulcers, so regular exams are key. Daily foot examination and appropriate moisturization along with blood glucose management can prevent and/or delay the progression of foot traumas.
Peripheral artery disease
Peripheral artery disease (PAD) is plaque (cholesterol) build-up in the arteries resulting in a decrease in blood flow to the legs and feet. Risk factors for PAD include diabetes, high cholesterol, high blood pressure, smoking, age (especially older than 60 years) and atherosclerosis. Atherosclerotic cardiovascular disease (ASCVD) that affects the legs and feet are thought to be due to the build-up of plaque in the blood vessels, narrowing the arteries.8,9,10
Symptoms include pain or cramping due to lack of blood flow while being physically active (e.g., walking) in the calf, thigh, buttock, or hip, which often resolves when the movement is stopped.9 Other signs can include hair loss on the legs and feet; decreased pulse in the feet (or sometimes the pulse cannot be felt); cold legs and feet; or sores on the legs or feet that don’t heal.8,9,10
Diagnosis
There are several different tests the doctor can order to help diagnose peripheral artery disease including an ankle-brachial index (ABI) that measures the blood pressure in the ankles and compares it with the blood pressure in the arms at rest and then after exercise. There are also imaging tests such as ultrasound, magnetic resonance angiography (MRA) and computed tomographic (CT) angiography that may be ordered.8,9,10
Treatment
Modifiable lifestyle factors are important including keeping blood glucose as close to the target range as possible, stopping smoking, losing weight if overweight or obese, managing blood pressure and cholesterol and taking medications (such as daily aspirin) that are prescribed. Depending on how blocked the artery is, surgery may be needed to bypass the blocked artery and return blood flow. Physical activity programs to improve the ability to walk further may also be helpful.8,9,10
Charcot joint
Charcot joint, also called neuropathic arthropathy or Charcot neuro-osteoarthropathy, most commonly affects the foot (Charcot foot) but the knee and wrist could be affected. In a person who has neuropathy, bone tissue begins to be destroyed in the area of nerve damage which can lead to irreversible foot deformity. Often there is some injury or trauma to the area when symptoms occur.8,11,12
Early diagnosis is the key to stop or slow the progression. Unfortunately, there are few early symptoms because of the underlying neuropathy (numbness, tingling and loss of sensation). Usually, people have a red, hot and swollen foot but not much pain when they go to the doctor. Healthy history, blood tests and imaging of the foot will be ordered to diagnose. Weight-bearing (i.e., standing) radiographs of the ankle and foot (special imaging) may be conducted to assess the bone and joint damage.8,11,12
Treatment includes offloading (not weight bearing on foot) and casting so the joint cannot move until the swelling goes down or fractures heal. People are closely monitored and assessed for the inflammation and swelling to reduce. Afterward, braces and special footwear is prescribed. Surgery is conducted only if absolutely necessary due to the risks and complications involved in that area (e.g., the foot has neuropathy).8,11,12
Prevention of Foot Complications
While managing diabetes can help reduce the risk of developing complications, simple foot interventions can also reduce serious foot issues and amputations by up to 80 percent.2,3 Diabetes healthcare providers should be conducting foot exams annually, if not more frequently, to evaluate if there are any signs of neuropathy, peripheral vascular disease, foot deformity, wounds, state of skin, or swelling/fluid retention. It is recommended that the doctor use a monofilament to test and then either a tuning fork, vibration, or pinprick. Ankle reflexes and temperature sensation may also be evaluated. In addition, people with diabetes can also help to avoid serious foot complications by:
- Keeping blood glucose as close to the target range as possible
- Managing blood pressure
- Managing cholesterol
- Getting regular physical activity
- Eating a healthy diet
- Stop smoking
- Drinking alcohol in moderation
- Getting regular sleep
- Managing stress
- Following preventative foot-care recommendations (e.g., looking at the bottom of the feet and lower legs each day to make sure there are no sores, cuts, or any objects in the foot, daily moisturization, etc.)
- Using specialized foot wear as prescribed by the doctor to prevent further foot complications
- Call the doctor if there are any changes to the skin, sores, or traumas so they can be treated early before they progress into more serious health issues
Psychosocial Aspects of Foot Complications
Since many of the diabetes foot complications can affect mobility and carrying out daily activities, it is not surprising that foot complications affect the quality of life, changes social roles and increases depression, anxiety and diabetes distress. Higher pain intensity also leads to a decrease in sleep and work productivity and an increase in healthcare costs, further adding stress.12,15,16,18 It has been noted that often these complications and their treatments are often more burdensome than managing diabetes itself, which is no surprise.17,18,19
When you have been diagnosed with a foot complication, it may be painful, limit your mobility or functioning, and affect your daily living. You may want to get some extra support to help you cope because dealing with a new health condition can be overwhelming and modifying your daily life, including needing help from others, can be even more difficult. Many people often need extra support in adjusting to their new normal. Talk to your diabetes health care provider about how you are feeling and your worries. They can recommend some practical tips for adjusting to your new norm and also refer you to a mental health provider that has experience in helping patients deal with diabetes complications. Taking care of yourself both medically and psychologically can help improve your overall quality of life as well as your physical and mental health.
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3. Krishnan S, Nash F, Baker N, Fowler D, Rayman G. Reduction in diabetic amputations over 11 years in a defined U.K. population: benefits of multidisciplinary team work and continuous prospective audit. Diabetes Care. 2008;31(1):99–101.
4. Hinchliffe RJ, Andros G, Apelqvist J, et al. A systematic review of the effectiveness of revascularization of the ulcerated foot in patients with diabetes and peripheral arterial disease. Diabetes Metab Res Rev. 2012;28(suppl 1):179–217.
5. Boulton AJM. The diabetic foot. Med Clin North Am. 2013;97(5):775–992.
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7. International Diabetes Federation. IDF clinical practice recommendations for managing Type 2 diabetes in primary care. 2017. Available at: www.idf.org/managing-type2-diabetes.
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11. Petrova, N., and Edmonds, M. (2016) Acute Charcot neuro‐osteoarthropathy. Diabetes Metab Res Rev, 32: 281– 286. doi: 10.1002/dmrr.2734.
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13. Varghese G.I., Mathew M., Marmur E., Varghese M.C. (2017) Dermatological Complications of Diabetes Mellitus; Allergy to Insulin and Oral Agents. In: Poretsky L. (eds) Principles of Diabetes Mellitus. Springer, Cham. https://doi.org/10.1007/978-3-319-20797-1_29
14. https://www.aad.org/public/diseases/a-z/diabetes-warning-signs
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Educational content related to diabetes complications is made possible with support from Allergan, an active partner of Beyond Type 1 at the time of publication. Editorial control rests solely on Beyond Type 1.
