Foot swelling is a common occurrence that can signal various health issues. For individuals with diabetes, swelling is often a symptom of underlying complications related to long-term high blood glucose levels, not the diabetes itself. Edema happens when excess fluid accumulates in the tissues, most noticeably in the lower extremities due to gravity. Recognizing the cause of this swelling is fundamental to diabetic foot care, as it may indicate a need for immediate medical attention.
How Diabetes Affects Circulation and Fluid Retention
Long-term, poorly controlled blood sugar damages the body’s vascular and renal systems. This damage creates two primary pathways leading to fluid accumulation and swelling. The first pathway involves damage to the blood vessels, particularly the delicate network of capillaries and veins in the legs.
High glucose levels contribute to the development of Peripheral Artery Disease (PAD), which involves the narrowing of arteries and reduces blood flow to the feet. The damage also affects the veins. The small valves within the veins that prevent blood from flowing backward begin to leak, a condition known as venous insufficiency.
This leakage causes blood to pool in the lower legs, resulting in fluid seeping out of the capillaries and into the surrounding tissues. The combination of poor arterial flow and inefficient venous return contributes to persistent peripheral edema.
The second major mechanism involves the kidneys. The filtering units can become damaged by high blood sugar, leading to a chronic loss of function. As the disease progresses, the kidneys become less efficient at removing waste and excess fluid from the body.
This impairment causes a systemic increase in fluid volume, which then collects in the lower body. In more advanced stages, the damage can lead to the loss of albumin protein. Albumin is responsible for maintaining pressure within the blood vessels, and its loss reduces the plasma’s ability to hold fluid, forcing it out of the bloodstream and into the tissues.
Swelling from Non-Diabetic Causes
Foot swelling is often caused by factors unrelated to diabetes-specific complications. One common non-diabetic cause is the side effect of certain medications taken to manage related conditions. For example, some blood pressure medications, particularly calcium channel blockers like amlodipine, are known to cause peripheral edema.
These medications cause the small arteries (arterioles) to widen, increasing pressure within the capillaries in the legs. This increase in pressure forces fluid out of the vessels and into the surrounding tissue. Other medications, including steroids, nonsteroidal anti-inflammatory drugs (NSAIDs), and certain diabetes drugs called thiazolidinediones, can also contribute to lower extremity edema.
Organ failure can disrupt the body’s overall fluid management. Congestive heart failure, where the heart does not pump blood effectively, causes blood to back up in the veins, leading to fluid accumulation in the lower body. Likewise, advanced liver disease, such as cirrhosis, can cause swelling due to low levels of albumin and the liver’s inability to regulate fluid.
Prolonged periods of sitting or standing can cause temporary swelling due to gravity and lack of muscle pump action. However, for people with diabetes, all cases of swelling should be taken seriously due to the heightened risk of complications.
What to Do About Swollen Feet
Managing swollen feet begins with optimizing the underlying condition. For immediate relief of mild, temporary swelling, elevating the feet above the level of the heart for 30 minutes can help the fluid drain back toward the torso. Reducing sodium intake also assists in minimizing fluid retention throughout the body.
The use of compression stockings can provide external pressure to prevent fluid from building up in the tissues. However, consult with a healthcare professional before using compression stockings, especially if peripheral artery disease is present, as they can sometimes interfere with blood flow. Regular, gentle exercise also helps by engaging the leg muscles to pump fluid back toward the heart.
Swelling requires immediate medical evaluation if signs such as warmth, redness, pain, or limitation to only one leg are present, as this may indicate a serious problem like a deep vein thrombosis (blood clot) or an infection. For individuals with diabetic neuropathy, swelling may be the only sign of a severe underlying issue because nerve damage masks pain.
Charcot foot is a serious complication resulting from nerve damage. It typically presents with noticeable unilateral swelling, warmth, and redness. If left untreated, this condition can cause the bones and joints to collapse, leading to severe foot deformity and a high risk of ulceration and infection.