Foot disease and diabetes

Dr Paula Diab stresses that every complication of foot disease relating to diabetes is preventable and gives guidelines to spot these complications in early stages.

Foot disease is probably one of the most feared aspects of diabetes. Almost everyone has a horror story about a friend or neighbour or sometimes tragically, a relative, who developed foot disease, gangrene or needed an amputation.

The statistics relating to foot disease are horrifying but what is worse, is that almost every single complication related to foot disease is entirely preventable. It’s not normal for people with diabetes to get foot ulcers and then need an amputation; it’s only through poor diabetes management that you lose sensation and circulation in the feet.

Educating yourself and knowing the signs and symptoms to look out for can radically improve your chances at retaining healthy feet despite having diabetes.

What causes diabetic foot disease?

You may have heard about macro- and microvascular complications related to diabetes. This refers to whether the large (macro) or small (micro) vessels in the body are affected. Foot disease can be caused by both macrovascular or microvascular disease which it is probably why is such a common complication.

Macrovascular disease occurs when blood circulation from the heart is diminished either through excessive glucose or cholesterol deposits in the vessels or narrowing due to high blood pressure. This reduces the blood flow into the distal peripheries and the feet are usually the first to show signs of this lack of circulation. Smoking and other cardiovascular risk factors will also enhance this risk and further slowdown blood flow.

Microvascular disease caused by persistently high glucose levels affects the nerves in the feet. When these become damaged, you may feel pain, tingling or even numbness in the feet.

These two mechanisms can also occur simultaneously when a loss of sensation in the feet can make it difficult to discern when you have a blister, minor cut or injury on the foot. As these minor injuries are left untreated, infection can set in causing bigger wounds or even ulceration. Due to blood flow being restricted, healing is further delayed, and the wound progresses even more.

Sometimes infections become so deeply invasive that intravenous antibiotics, surgical debridement or hospitalisation are required. High blood glucose levels can cause the arteries to become stiff and prevent blood flow to the feet.

What are the signs and symptoms of foot disease?

The most common symptoms of damage to the feet is increased swelling of the legs and feet or a change in skin colour on the feet. This usually manifests as a purple discolouration of the skin around the ankles or mottling of the skin. You may also notice a decrease in the hair growth on the top of your feet or lower leg.

All these symptoms are due to the decreased blood flow and poor circulation of blood from the heart. Nerve damage initially causes burning or tingling in the feet and then develops into a lack of sensation and numbness. This may happen intermittently at first but then begins to become more obvious and more difficult to treat.

Delayed healing of wounds, cracks and blisters on the feet are more advanced signs of foot damage.

Please also pay careful attention to ingrown toenails, warts, corns, calluses, bunions and hammertoes. These minor deformities often result in abnormal gait (the manner in which you walk) and as a result puts pressure on areas of the feet where you would not normally. This results in damage to the nerves and further enhances the risk of microvascular damage.

There are also nerves in the body over which you have no control. These are called autonomic nerves and control functions such as digestion, sweating and temperature regulation in the body. They too can be damaged by diabetes and may cause dryness, cracks, fissures, blisters and callus formation in the feet, all of which may lead to secondary infections and damage.

How should you take care of your feet?

As with all complications of diabetes, the basic control of glucose levels is of huge importance. Check your levels regularly and seek expert advice when they are not in target. Regular exercise can also prevent foot disease and promote good blood flow in the feet.

All that we require with regard to exercise is that you are simply more active today than you were yesterday. Aim to do 20-30 minutes of moderate intensity cardiovascular activity a day on most days of the week. Walking, jogging, swimming, cycling or even sustained household chores, such as mowing the lawn or vacuuming, may count towards this activity.

Other important footcare advice

  • Wash your feet every day with lukewarm (not hot) water and mild soap.
  • Dry your feet well, especially between the toes. Use a soft towel and pat gently but don’t rub the feet too vigorously.
  • Keep the skin of your feet smooth by applying a cream or lanolin lotion, especially on the heels. If the skin is cracked, talk to your doctor about how to treat it.
  • Keep your feet dry by dusting them with non-medicated powder before putting on shoes, socks or stockings.
  • Check your feet every day. You may need a mirror to look at the underside of your feet. Call your doctor if you have redness, swelling or pain that doesn’t go away, numbness or tingling in any part of your foot.
  • Don’t treat calluses, corns or bunions without talking to your doctor first.
  • Cut toenails straight across to avoid ingrown toenails. It might help to soak your toenails in warm water to soften them before you cut them. File the edges of your toenails carefully.
  • Don’t let your feet get too hot or too cold.
  • Don’t walk barefoot. This is to prevent injuries to your feet.
  • Avoid putting your feet in front of a fire in winter to warm then, if they have lost sensation you could end up with burns or blisters which you do not feel.
  • Avoid using hot water bottles to warm your feet in winter as the bottle may be too hot and also cause blisters if your nerves are damaged.

Choosing footwear

You certainly don’t need high fashion or expensive footwear in diabetes. But you also don’t have to wear big bulky boots that look ugly. Here are important tips to consider when choosing your footwear:

  • Try not to wear shoes without socks as they protect the feet and prevent excessive sweating and pressure from the shoes.
  • Ensure that your socks are good quality and not worn or frayed that will cause damage to the feet.
  • Avoid open sandals or shoes where feet are not adequately protected from external injury.
  • Avoid high-heeled shoes and shoes with pointed toes that will change the architecture of the feet.
  • Wear well-padded socks or stockings in winter. Don’t wear stretch socks, nylon socks, socks with an elastic band or garter at the top, or socks with inside seams as these place undue stress on the skin and constrict blood flow.
  • Don’t wear uncomfortable or tight shoes that rub or cut into your feet. If you’ve had problems before because of shoes that didn’t fit, you may want to be fitted for a custom-moulded shoe.
  • Talk to your doctor or podiatrist before you buy special shoes or inserts.
  • Shop for new shoes at the end of the day when your feet are a little swollen. If shoes are comfortable when your feet are swollen, they’ll probably be comfortable all day.
  • Break in new shoes slowly by wearing them for no more than an hour a day for several days.
  • Change socks and shoes every day. Have at least two pairs of regular shoes so you can switch pairs every other day.
  • Look inside your shoes every day for things like gravel or torn linings. These things could rub against your feet and cause blisters or sores.

Seek help

If you do develop some type of wound on your feet, please get it seen to as soon as possible. Don’t wait until it’s too late before you seek help.

Your doctor, diabetic nurse educator or podiatrist can all examine the feet on a regular basis to test a variety of different functions and help prevent further injury and infection.

It’s also good practice to examine your own feet on a regular basis. Look for changes in skin colouration, hair growth and new sores or blisters that may have developed. Look at your feet at the end of the day when you remove your shoes and make sure that the shoes are not damaging your feet in any way. You should also make sure that a healthcare practitioner examines your feet at least once a year. If there are any concerns or changes, you should see a podiatrist immediately and treat the problem in its early stages.

The old adage prevention is better than cure is certainly true of foot disease. Regular exercise, monitoring your blood glucose levels and keeping them well-controlled and stopping smoking will go a long way to ensuring that you don’t land up under the surgeon’s knife or with complex infections.

Dr Paula Diab


Dr Paula Diab is a diabetologist at Atrium Lifestyle Centre and is an extra-ordinary lecturer, Dept of Family Medicine, University of Pretoria.

Header image by FreePik