If you live with diabetes, you have probably heard how important it is to look after your feet. Meanwhile, swelling is one of the changes I see most often in my practice. Diabetic swollen feet can come from several causes. Some are minor, like sitting too long on a hot day. Others, however, point to problems with circulation, the kidneys, the heart, or an infection. In this article, I explain the most common causes and the signs that need prompt care. I also share what you can do at home.
Key Takeaways
- Diabetic swollen feet can come from poor circulation, vein problems, kidney or heart disease, medicines, or infection.
- Nerve damage can hide injuries, so a swollen foot may be the first clue that something is wrong.
- A red, hot, swollen foot, a wound that will not heal, or swelling in only one leg needs prompt care.
- Daily foot checks, good blood sugar control, walking, and leg elevation all help.
- Sudden chest pain or shortness of breath with leg swelling can be an emergency. Call 911.
How Diabetes Affects Your Feet
Over time, high blood sugar can damage both blood vessels and nerves. As a result, two problems often show up together in the feet.
First, diabetes speeds up plaque buildup in the arteries. This can lead to peripheral arterial disease (PAD), which reduces blood flow to the legs and feet. Second, high blood sugar can also damage the nerves, a condition called neuropathy. So you may not feel a blister, cut, or sprain. A swollen foot is sometimes the only sign that an injury has happened.
The National Institute of Diabetes and Digestive and Kidney Diseases explains more about how diabetes affects the feet.
Common Causes of Diabetic Swollen Feet
Swelling, also called edema, happens when fluid builds up in the tissues. So it helps to know where the fluid comes from. In people with diabetes, these are the most common reasons.
- Vein problems. Weak valves in the leg veins let blood pool in the lower legs. This often causes swelling that is worse at the end of the day.
- Kidney disease. Diabetes is a leading cause of kidney damage. When the kidneys cannot remove extra fluid and salt, the feet and ankles may swell.
- Heart problems. Diabetes raises the risk of heart disease. As a result, a weak heart can cause fluid to collect in the legs.
- Medicines. Some diabetes and blood pressure medicines can cause mild swelling. Never stop a medicine on your own, though. Instead, ask your doctor.
- Injury or infection. Because of nerve damage, a sprain, fracture, or skin infection can go unnoticed until the foot swells.
- Blood clots. Swelling in only one leg, with pain or warmth, can be a sign of a clot.
- Too much salt and too little movement. Both can also make fluid buildup worse.
For a broader look, see our page on leg swelling.
Charcot Foot: A Serious Cause of Swelling
Charcot foot is a less common but serious problem in people with neuropathy. Because the nerves are damaged, the bones in the foot can weaken, break, or shift without much pain. At first, the foot often looks red, warm, and swollen. Over time, the shape of the foot can change, which raises the risk of sores.
Because it can look like an infection or a sprain, Charcot foot is easy to miss. For this reason, a warm, swollen foot in someone with diabetes and neuropathy should be checked quickly. Early treatment usually means taking pressure off the foot with a cast or special boot.
Warning Signs That Need Prompt Care
Some swelling is mild and comes and goes. Still, certain signs should never wait. Call your doctor soon if you notice any of the following.
- A foot that is red, hot, and swollen
- A sore, blister, or cut that is not healing within a week or two
- Swelling in only one leg, especially with calf pain
- Skin that looks pale, blue, or dark, or a foot that feels cold
- Foot or leg pain at rest or at night, which can be a sign of rest pain
- Fever, drainage, or a bad smell from a wound
- A change in the shape of your foot
If leg swelling comes with sudden chest pain or shortness of breath, call 911. This can be a sign of a blood clot in the lungs or a heart problem.
In addition, poor blood flow makes wounds heal slowly. Over time, small sores can turn into arterial ulcers. You can learn more in my article on diabetes and peripheral artery disease.
Simple Ways to Care for Your Feet at Home
Daily habits make a real difference. Here is what I recommend to my patients.
- Check your feet every day. Look for swelling, cuts, blisters, or color changes. If needed, use a mirror or ask a family member for help.
- Keep blood sugar in your target range. In fact, good control protects both nerves and blood vessels.
- Walk regularly, if your doctor says it is safe. Walking helps blood flow in the legs.
- Raise your legs when you sit or rest.
- Limit salt, which makes the body hold on to fluid.
- Wear well-fitting shoes and socks. Also, never walk barefoot, even at home.
- Do not smoke. Smoking narrows the arteries and slows healing.
Compression can help some types of swelling. However, it is not safe for everyone. If you have poor arterial blood flow, tight compression can do harm. So please get checked before you use compression stockings.
How I Evaluate Swollen Feet
First, I start with a careful exam of the skin, pulses, and any wounds. Then I often check blood flow with simple, painless tests, such as an ankle-brachial index or an ultrasound. With these results, we can find the cause and build a plan. If an artery is blocked, minimally invasive treatments such as angioplasty can restore blood flow.
Coastal Vascular Center is a small, physician-owned practice, not a corporate chain. You will see me at every visit, and I personally perform every procedure. There is no hand-off to a physician assistant or nurse practitioner.
Get Swollen Feet Checked With Dr. Ayar
Living with diabetes and dealing with swollen feet, slow-healing sores, or leg pain? We can check your circulation and help protect your feet. You will see Dr. Ayar at every visit in Pearland or Lake Jackson.
