What is Foot Swelling?

Foot swelling—also called edema—occurs when excess fluid builds up in the tissues of the feet and ankles. It can affect one or both feet and may be temporary (after a long day of standing or travel) or persistent, signaling an underlying medical condition. While mild swelling often improves with rest and elevation, sudden or severe swelling should be evaluated by a healthcare provider.

Causes

Swollen feet can result from a wide range of factors, including:

  • Lifestyle and environment

    • Prolonged standing or sitting

    • Hot weather (blood vessels expand, causing fluid leakage)

    • High‑salt diet leading to fluid retention

  • Injury or trauma

    • Sprains, fractures, or overuse injuries

  • Medical conditions

    • Venous insufficiency – weakened leg veins that allow blood to pool

    • Heart disease or heart failure – fluid backs up into the legs and feet

    • Kidney disease – impaired fluid balance causes swelling

    • Liver disease – low protein levels allow fluid to leak into tissues

    • Lymphedema – blockage or damage to lymphatic drainage

    • Blood clots (DVT) – sudden swelling in one leg, often painful and dangerous

  • Other factors

    • Pregnancy (common in later trimesters)

    • Medications (blood pressure drugs, steroids, hormones, antidepressants, NSAIDs)

    • Infections, especially in people with diabetes

Symptoms

Typical signs of foot swelling include:

  • Puffiness or enlargement of the feet and ankles

  • Shiny, stretched, or tight skin

  • Pitting edema – when pressing on the swollen area leaves a dimple

  • Heaviness, stiffness, or discomfort when walking

  • Redness, warmth, or tenderness if infection or clot is present

  • Shortness of breath or chest pain if swelling is linked to heart or lung problems (emergency warning sign)

Diagnosis

To determine the cause of swollen feet, providers may use:

  • Medical history and physical exam – checking for pitting, tenderness, or asymmetry

  • Blood tests – to evaluate kidney, liver, or heart function

  • Imaging – X‑rays for injury, ultrasound for blood clots, echocardiogram for heart failure

  • Urinalysis – to check for protein loss in kidney disease

  • Vascular studies – to assess circulation and vein health

Nonsurgical Treatment

Treatment depends on the cause, but common conservative measures include:

  • Elevation – raising feet above heart level to reduce fluid buildup

  • Compression socks or stockings – to improve circulation

  • Hydration – drinking enough water to prevent fluid retention

  • Dietary changes – reducing salt intake, eating magnesium‑ and potassium‑rich foods

  • Exercise and movement – walking, stretching, or ankle pumps to improve blood flow

  • Weight management – reducing strain on feet and circulation

  • Medications – diuretics (“water pills”) may be prescribed for heart, kidney, or liver‑related edema

When is Surgery Needed?

Surgery is not a treatment for swelling itself, but may be required if the underlying cause is structural or severe, such as:

  • Venous insufficiency – vein procedures to improve circulation

  • Severe lymphedema – surgical drainage or lymphatic reconstruction in rare cases

  • Blood clots (DVT) – urgent intervention to prevent life‑threatening complications

  • Advanced organ disease – procedures like heart valve surgery, dialysis access, or liver transplant may be necessary depending on the root cause