Diabetic foot care

Over the years, high blood sugar can injure the nerves and circulation in the feet. Reduced feeling means a blister, cut, or pressure sore can go unnoticed, and reduced blood flow slows healing, so a small injury can turn into a serious ulcer or infection. Daily foot care and regular foot exams help prevent these problems and catch them early.

Signs that diabetes may be affecting your feet include:

• Numbness, tingling, burning, or pain in the feet
• Reduced ability to feel temperature, pressure, or pain
• Dry, cracked skin
• Cold feet, color changes, or cuts that heal slowly, which can reflect poor circulation
• Calluses, especially ones with dark spots of dried blood inside
• Blisters or open sores (ulcers), sometimes without any pain
• Swelling, redness, or warmth, or a change in the shape of the foot

Over time, high blood sugar can injure the nerves in the feet (peripheral neuropathy) and reduce the blood flow that reaches them. Without the warning signal of pain, pressure from a tight shoe or a stone in the shoe can damage the skin without being noticed. Poor circulation slows healing and makes infection harder to fight.

Less often, nerve damage allows the bones of the foot to break down or shift without much pain, a condition called Charcot foot, which can change the shape of the foot.

The risk of foot problems is higher with:

• Blood sugar that has been high over a long period
• Smoking, which further reduces blood flow
• A previous foot ulcer or amputation
• Changes in foot shape, such as bunions or hammertoes, that create pressure points
• Shoes that do not fit well

Your feet should be checked at diabetes visits — take off your shoes and socks so they can be examined. At least once a year, a thorough foot exam checks the skin, nails, foot shape, feeling (often with a simple touch test using a thin filament), and the pulses in your feet. People with numbness, poor circulation, changes in foot shape, or a past ulcer need closer and more frequent checks.

When a sore, swelling, or infection is found, the evaluation may include X-rays or other imaging of the bone, tests of blood flow, and blood tests.

Daily foot care is the foundation:

• Check both feet every day, including the soles, heels, and between the toes; use a mirror or ask someone to help if needed
• Wash your feet daily in warm — not hot — water, testing the temperature with your hand or elbow, and dry them well, especially between the toes
• Moisturize dry skin on the tops and soles, but not between the toes
• Trim toenails straight across and smooth the edges; have a foot specialist trim thick or ingrown nails, or nails you cannot see or reach well
• Do not cut corns or calluses or use medicated pads or liquid removers; have a clinician treat them
• Wear shoes and socks at all times, even indoors, and check inside your shoes before putting them on
• Choose well-fitting shoes with room for your toes, break in new shoes gradually, and ask whether special shoes or inserts are right for you
• Protect your feet from heat and cold — avoid heating pads, hot water bottles, and hot pavement
• Keep blood flowing by not smoking, staying active, and putting your feet up when sitting

Keeping blood sugar in your target range, with help from your care team, helps protect the nerves and blood vessels.

When a problem develops, treatment depends on the cause. A foot ulcer is treated by taking pressure off the area with a special cast, boot, or shoe, removing dead tissue, and treating any infection. Charcot foot is usually treated first by protecting the foot in a cast that keeps weight off it, followed by a protective boot and then custom shoes or braces. Surgery may be needed for a deformity that keeps causing sores, for an unstable foot, or for a serious infection.

A diabetic foot ulcer or Charcot foot can take weeks to months to heal, and healing depends on keeping pressure off the foot consistently. Because problems can return, protective footwear, daily checks, and regular foot exams continue after healing.

• Keep blood sugar in your target range
• Do not smoke
• Inspect your feet every day and never walk barefoot
• Wear well-fitting shoes and clean, dry, padded socks without tight bands
• Have your feet examined at your visits, with a full foot exam at least once a year