The short answer
New pain and swelling in one leg can be a sign of deep vein thrombosis, particularly after surgery or reduced mobility. Seek urgent medical assessment. Leg symptoms with breathlessness or chest pain require emergency care immediately.
Understanding the problem
A clot in a deep vein can travel to the lungs. Symptoms cannot reliably distinguish a clot from other causes of postoperative swelling at home. A clinician may arrange ultrasound and other assessment rather than relying on appearance alone.
Care and next steps
Take any prescribed clot-prevention treatment exactly as directed and follow your permitted movement plan. Do not start, stop or change blood-thinning medicine based on this article. Tell the team about previous clots and any new bleeding concerns.
Prepare for your consultation
Keep your discharge summary and medication list accessible. Before surgery, ask who will explain your prevention plan and how long each medicine is intended to continue. If symptoms arise, note when they began and which leg is affected, but do not delay urgent care to collect paperwork. The routine appointment number on this website is not an emergency response service.
Common questions
Can I wait for my next clinic visit with new calf swelling?
New unexplained one-sided swelling needs urgent assessment rather than waiting for a routine review.
Medical sources & further reading
This patient education guide was approved for publication by Dr Shahrukh Khan on 11 September 2026. It cannot diagnose your symptoms or replace a personalised clinical assessment. Editorial policy · About the doctor.