Diabetic foot

What is diabetic foot?

Diabetic foot problems happen when there is damage to the nerves and blood vessels in your feet, usually after high blood sugar levels over a long period. This can cause numbness and poor circulation, which makes cuts, blisters and infections much slower to heal.

What are the symptoms of diabetic foot problems?

Symptoms include:

• cuts, blisters, calluses or sores that don't heal
• changes to your skin or toenails
• bleeding, or fluid or pus coming from the skin
• a foul smell
• pain, or a burning or tingling feeling
• numbness, or a loss of feeling in your foot
• skin discolouration
• swelling.

Some people feel pain, burning or pins and needles in their feet, often worse at night. Others lose sensation instead, so they may not notice a problem until it's checked during an examination. If a foot changes colour, especially alongside new numbness or pain, this needs urgent attention.

Left untreated, foot problems can lead to two serious complications: gangrene, where tissue dies because blood flow has stopped, and Charcot foot, a rare complication of nerve damage that can collapse the joints in your foot. Both need prompt medical attention, and gangrene is a medical emergency.

What are the causes of diabetic foot problems and who is at risk?

There are two main underlying causes. The first is diabetes-related nerve damage (neuropathy), which makes it harder to feel problems with your feet, so injuries can go unnoticed. The second is peripheral artery disease, which reduces blood flow to your legs and feet and makes wounds slower to heal.

Poor foot care adds to the risk, including:

• wearing shoes that don't fit well
• walking around barefoot
• not treating cuts and sores with basic first aid.

Are there different types of foot problems?

Foot ulcers (open sores) are one of the most common problems, and typically develop where your foot repeatedly rubs or presses against a shoe or another surface. Ulcers can become infected, and if the infection doesn't clear up, part of the foot or toe sometimes needs to be surgically removed.

Other skin, nerve and circulation-related problems that can affect your feet include:

• cuts, burns and blisters that don't heal
• dry, cracked skin
• corns and calluses
• fungal infections, such as athlete's foot and toenail fungus
• ingrown toenails
• hammertoes and bunions.

A bunion is a bony bump that forms at the base of your big toe as the bones at the front of the foot shift out of position. If you have diabetes, it's recommended you get specialist podiatry assessment for a bunion rather than manage it yourself.

Two complications need particular care. Gangrene is a medical emergency where blood stops flowing to part of the body and the tissue dies. Charcot foot is a rare complication of nerve damage that, if not treated soon enough, can make the joints in your foot collapse and permanently affect how your foot works.

How are diabetic foot problems diagnosed?

A healthcare provider will usually ask about your symptoms and your diabetes history, then examine your toes, feet and legs, including touching them with various tools to check for numbness. If you have an ulcer or blister, they'll also check it for signs of infection.

For a suspected ulcer or a deeper problem, they may also:

• recommend an X-ray or MRI scan to look for issues below the skin
• take a small sample of skin or discharge (a biopsy) to test for infection.

It's recommended you have a diabetic foot check with a trained healthcare professional every 12–24 months, which will also tell you your risk level for developing foot problems. It's worth asking your GP, nurse or podiatrist to look at your feet at every appointment too, even if you haven't noticed anything wrong.

How are diabetic foot problems treated?

Non-surgical treatments

The most important step is managing your blood sugar well, to help prevent or slow down nerve and blood vessel damage. Technology such as continuous glucose monitoring can help with this, alongside regular reviews with your diabetes team.

If you have a foot ulcer, treatment may include:

• cleaning the wound and draining any fluid or pus
• removing dead or infected tissue (debridement)
• special bandages or ointments to protect the wound and absorb fluid
• a wheelchair or crutches to take weight off the affected foot (offloading)
• antibiotics, taken by mouth or given into a vein, to treat infection.

Surgical treatments

Depending on how severe an infection is, you may need to be admitted to hospital. If an infection doesn't respond to treatment and risks spreading further, part of the toe, foot or leg is sometimes surgically removed (amputated) to protect the rest of the body. Getting treatment early greatly reduces the risk of this happening.

When should I see a doctor?

Contact your podiatrist or GP if you notice:

• a cut, blister or bruise that hasn't started to heal within a few days
• red, warm or painful skin on your foot
• a sore that won't heal
• loss of feeling, or a reduced ability to sense heat or cold
• a change in the colour, temperature or shape of your foot
• thick, yellow toenails, or an ingrown toenail
• a fungal infection between your toes.

Take the weight off the affected foot, and cover any wound with a clean, sterile dressing if you have one, while you arrange to be seen.

Get emergency help (go to A&E, or call 999) if you have signs of gangrene, such as:

• skin changing colour, from red or brown to purple or greenish-black
• severe pain, or a sudden loss of feeling
• a foul-smelling discharge from a sore or blister
• fever, chills or a fast heartbeat.