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Blood clot risk around surgery — and "is this leg a clot?"
Two checkers in one: before surgery, see your personal clot (DVT) risk and why your team may prescribe stockings or blood-thinner injections. After surgery, check whether new leg symptoms fit the pattern of a clot — using the same published scores clinicians use.
🚨 Skip the calculator and call emergency services (911) now if you have:
sudden breathlessness · chest pain (especially worse breathing in) · coughing blood · a racing heart with faintness · collapse. These can mean a clot has reached the lungs — minutes matter, scores don't.
Quick answer
Surgery is a major trigger for leg clots (DVT). Your risk is personal — age, the operation type, cancer, previous clots and immobility all add up (the Caprini score); higher scores are why teams prescribe compression stockings or blood-thinner injections. After surgery, the clot pattern to watch is ONE calf becoming swollen, tender, warm or discoloured — contact your team the same day. Sudden breathlessness or chest pain is an emergency: call 911, don't score anything.
Frequently asked questions
Why do I need blood thinner injections or compression stockings after surgery?
Surgery is one of the strongest triggers for deep-vein clots (DVT): you're lying still, the operation itself activates clotting, and some operations (hip and knee replacements especially) irritate the large leg veins directly. Your team estimates your personal risk — commonly with the Caprini score this tool uses — and matches the protection to it: walking early for the lowest risk, compression stockings or calf pumps in the middle, and blood-thinner injections (sometimes for weeks after discharge) at higher scores.
What are the warning signs of a blood clot after surgery?
In the leg (DVT): one calf becoming swollen, warm, tender or discoloured — usually one side, not both. In the lungs (PE, an emergency): sudden breathlessness, chest pain that's worse on breathing in, coughing blood, a racing heart, or feeling faint. Any of the lung signs mean call emergency services now — don't score anything, don't wait.
How accurate is this calculator?
It uses the same published scores clinicians use — Caprini (2005) for surgical clot risk and the Wells score (2003) for how likely new leg symptoms are to be a DVT. But it's an educational estimate: it can't examine your leg, and only an ultrasound can actually rule a DVT in or out. Use it to understand your risk and to decide how urgently to call — not instead of calling.
Both my legs are a bit swollen after surgery — is that a clot?
Mild swelling in BOTH legs is common after surgery and usually isn't a DVT, which is typically one-sided. The pattern that matters is one leg (especially one calf) becoming more swollen, tender, warm or discoloured than the other. If that happens, contact your surgical team the same day.
Is my information saved?
No. Everything is scored on your own device and nothing you tick is stored or sent anywhere.