A swollen and painful calf: what to do

One-sided swelling without a clear minor injury deserves particular attention. Do not massage the calf or exercise through the symptoms until a clinician has assessed an unexplained clot-like presentation.

A muscle strain or contusion can present with calf pain, swelling and bruising, often after a clear movement or impact. Achilles tendinitis more often presents with pain and stiffness near the tendon, although irritation around the lower calf and ankle can coexist.

A deep-vein blood clot can present with swelling, warmth, tenderness or colour change, but symptoms alone cannot confirm or exclude it. Infection, a ruptured cyst and circulation problems are other possibilities. The timing, side affected, recent injury, mobility, travel, surgery, pregnancy and medicines help guide assessment.

Compare both legs without repeatedly squeezing the sore area. Note when the swelling began, whether it followed an injury, and whether there is warmth, redness, bruising or breathlessness. Arrange same-day medical advice for new unexplained one-sided calf swelling or pain.

After a clear mild muscle injury, pause the provoking activity and protect the leg from further strain while arranging review if symptoms are substantial. Avoid deep massage until a clot or acute tissue injury has been ruled out. Treatment depends on the cause, so stretching and sports massage are not appropriate first responses to unexplained swelling.

Call emergency services for calf symptoms accompanied by sudden shortness of breath, chest pain, coughing blood, fainting or severe weakness. Urgent assessment is also needed if the leg becomes cold, pale or numb; swelling rapidly increases; redness spreads with fever; or severe pain follows an injury and you cannot bear weight.

Ask whether blood-clot testing or imaging is needed, which movements are safe, and what changes should trigger emergency care. Mention recent travel or immobility, an operation, pregnancy or recent birth, hormone medicines, cancer treatment, previous clots, injuries and new medication because these details can alter the assessment.