What is swelling? | Swelling in the legs, ankles, or feet | Cardiology Made Clear with Dr. Freeman

← Swelling in the legs, ankles, or feet: the short explanation

All 6 sections, including text and pictures · 12 pages

What should I do now?

Call 911

Call 911 for new or unexplained chest pressure that persists or returns, severe trouble breathing, collapse without normal recovery, or sudden face/arm weakness or trouble speaking. Do not drive yourself.

Contact your care team

Contact your care team promptly for increasing swelling, rapid weight change, or worsening breathlessness.

Keep your care plan

Track weight and swelling as instructed. Do not change a water pill without a specific plan.

Patient summaries & logs →

SECTION 1

What is swelling in the legs, ankles, or feet?

Swelling occurs when extra fluid collects in the tissues. This is called edema. Shoes may feel tighter, sock marks may deepen, or the skin may look stretched.

Illustrative comparison of ankles and feet without swelling and with edema. — Swelling can have several causes. Its appearance alone does not identify the cause.

Swelling can affect one leg or both. It may vary with standing, sitting, or time of day. Leg swelling does not automatically mean heart failure.

Sources & further readingMedlinePlus: Leg and ankle swelling Cleveland Clinic: Venous insufficiency NHLBI: Deep vein thrombosis and blood clots

Updated October 2026. Educational information; your own care plan may differ. Medical illustrations are simplified examples for teaching.