What should you know about normal swelling after knee replacement?

Surgery irritates tissues around the knee, so fluid can collect around the joint and nearby soft tissues. The knee may feel tight, look fuller, and bend less easily; swelling can also become more noticeable after standing or physiotherapy. The amount and duration vary with the operation, activity, circulation, and individual healing. A gradual pattern that eases with rest and elevation is more reassuring than swelling that rapidly increases, becomes hot and red, or is paired with a new loss of function. Swelling itself is a symptom, not a diagnosis, and it can have causes unrelated to the operation, including a Baker's cyst, gout, knee bursitis, or a blood clot.

Follow the surgeon’s instructions for walking, exercises, wound care, and prescribed medicines. Elevate the leg as advised, use cold therapy only with a protective layer and for the recommended periods, and avoid suddenly increasing activity. Gentle ankle movements and regular short walks may support circulation when your team has approved them. Do not place a pillow directly behind the knee for long periods unless instructed, because maintaining the planned position can matter for regaining movement. Keep notes on swelling, pain, temperature, and daily activity so changes are easier to describe.

Contact the surgical team promptly for rapidly increasing swelling, spreading redness, wound drainage, fever, worsening pain, or a knee that becomes much hotter than before. Seek emergency help for sudden breathlessness, chest pain, coughing blood, fainting, or new one-sided calf pain and swelling. Urgent assessment is also needed if the foot becomes cold, pale, numb, or difficult to move. A clinician may examine the knee and, when appropriate, consider joint aspiration to assess or relieve fluid.

Does my swelling follow the expected recovery pattern? How much walking and exercise should I do now? Which elevation and cold-therapy method is suitable? How should I protect the wound? Which changes mean I should call today, and which require emergency help?