What Is the Cause of Swelling in the Feet and Ankles?

Swelling in the feet and ankles is a common concern that can affect people of all ages. It may result from standing or sitting for long periods, dietary habits, minor injuries, or medical conditions involving the heart, kidneys, or liver. Because the feet and ankles are the lowest parts of the body, fluid tends to collect there more easily. While mild swelling is often temporary and manageable at home, persistent, painful, or uneven swelling in the feet or ankles may indicate a more serious underlying issue. Understanding what causes swelling in both the feet and ankles helps determine when self-care is sufficient and when medical evaluation is necessary.

If swelling is sudden, severe, or accompanied by pain, redness, or shortness of breath, visit our Austin emergency room.

Causes of Swelling in the Feet and Ankles

Swelling in the feet and ankles medically known as edema occurs when excess fluid builds up in the tissues. Because gravity pulls fluid downward, the lowest parts of the body, particularly the feet and ankles, are most commonly affected. While mild swelling may be temporary and harmless, persistent, painful, or uneven swelling in the feet or ankles can signal an underlying health condition that requires evaluation.

Common and Benign Causes

Many cases of swollen feet and ankles are related to everyday habits or temporary bodily changes and often improve with rest and simple care:

Prolonged standing or sitting: Remaining in one position for long periods allows fluid to pool in the feet and around the ankles, especially during work hours or long travel.

High salt intake: Excess sodium causes the body to retain fluid, leading to swelling in the lower legs, ankles, and feet.

Pregnancy: Hormonal changes and increased blood volume can cause swelling in the ankles and feet; sudden or severe swelling may indicate preeclampsia and should be evaluated.

Hormonal fluctuations: Menstrual cycles or menopause can trigger temporary fluid retention affecting both ankles and feet.

Hot weather: Heat causes blood vessels to widen, allowing fluid to leak into surrounding tissues, often noticeable around the ankles first.

Circulatory and Fluid Balance Causes

When circulation or fluid regulation is impaired, swelling often becomes more persistent and noticeable in both the ankles and feet:

Venous insufficiency: Weak or damaged leg veins struggle to return blood to the heart, causing fluid buildup around the ankles and lower legs that may extend into the feet.

Lymphedema: Damage or blockage in the lymphatic system leads to chronic swelling, commonly affecting the feet and ankles and sometimes progressing upward.

Heart failure: Reduced pumping ability allows fluid to accumulate in dependent areas, typically starting in the ankles and feet.

Kidney disease: Poor kidney function causes the body to retain salt and water, resulting in swelling of the feet and ankles.

Liver disease: Low protein levels in the blood allow fluid to leak into tissues, leading to noticeable swelling in the ankles and feet.

If swelling worsens, affects one ankle or foot more than the other, or does not improve with rest, search for an Emergency Room Near Me to rule out serious circulatory or organ-related causes.

Injury and Infection

Localized swelling involving the feet or ankles may result from injury or infection:

Injuries: Sprains, strains, fractures, or ligament damage in the ankle or foot can cause swelling, bruising, and pain due to inflammation.

Infections: Skin or soft tissue infections such as cellulitis may cause swelling that feels warm, red, and tender, often affecting the ankle and spreading into the foot.

Blood Clots and Vein Issues

Some causes of ankle and foot swelling require urgent medical attention:

Deep vein thrombosis (DVT): A blood clot in a deep leg vein can cause sudden swelling, often starting in the ankle or calf and extending into the foot, along with pain, warmth, or redness.

Medication-Related Swelling

Certain medications can interfere with fluid balance and lead to swelling in the ankles and feet:

Blood pressure medications, particularly calcium channel blockers

Hormones such as estrogen or corticosteroids

Nonsteroidal anti-inflammatory drugs (NSAIDs)

Some diabetes and antidepressant medications

Medication-related swelling should be discussed with a healthcare provider, especially if it becomes persistent or uncomfortable.

How to Reduce Swelling in Feet and Ankles

Preventing swelling in the feet and ankles involves supporting circulation and healthy daily habits:

Elevate feet and ankles above heart level regularly

Stay active with walking or gentle leg exercises

Wear supportive shoes and compression socks

Limit high-sodium foods and stay hydrated

Avoid prolonged sitting or standing

Monitor medications and underlying health conditions

Consistent habits can significantly reduce ankle and foot swelling over time.

When to Seek Medical Attention

Seek medical care if swelling in the feet or ankles:

Occurs suddenly or affects only one foot or ankle

Is accompanied by redness, warmth, or pain

Makes walking or movement difficult

Occurs with shortness of breath or chest pain

Key Takeaways

Swelling in the feet and ankles can result from lifestyle factors, injuries, circulation problems, or serious medical conditions affecting the heart, kidneys, or liver. Mild swelling often improves with lifestyle adjustments, while persistent or painful swelling requires medical evaluation. Monitoring symptoms such as pain, redness, warmth, or breathing difficulty helps determine when professional care is needed. Early attention supports better circulation, reduces discomfort, and prevents complications.