In short. Surgery changes how blood flows and clots. A deep vein thrombosis usually appears in one leg: calf swelling, a tight cramping ache that does not settle, warmth or redness. If part of the clot reaches the lungs, it becomes a pulmonary embolism — sudden breathlessness, chest pain on breathing, coughing blood, faintness. That is an emergency; call services and do not drive yourself.
Key points
- One-sided calf swelling with pain or warmth needs same-day assessment.
- Both legs swelling after surgery is usually ordinary.
- Pulmonary embolism signs are breathlessness, chest pain, coughing blood, collapse.
- Do not massage the leg or apply heat while a clot is suspected.
- Prevention: compression, movement, fluids, and sometimes blood thinners.
Why is the risk raised?
Blood left moving slowly in a vein tends to clot. After a long operation the legs may be still for hours; afterwards, pain, dressings, and sedation keep them still for longer. Abdominal, pelvic, and leg operations carry higher risk, as do longer procedures, older age, smoking, obesity, pregnancy, and a personal or family history of clots. Hospitals use compression stockings, mechanical pumps, early walking, fluids, and sometimes blood-thinning medicine.
What are the signs of a clot in the leg?
A deep vein thrombosis usually appears in one leg. The calf may swell and ache in a tight, cramping, or throbbing way that does not settle with rest. The skin may look red or discoloured and feel warm. The difference is usually one-sided, so compare the two calves.
| DVT (leg) | Pulmonary embolism (lung) | |
|---|---|---|
| Swelling | One calf | Usually none |
| Pain | Calf, cramping, persistent | Chest, worse on breathing |
| Skin | Red, warm, discoloured | — |
| Breathing | Normal | Sudden shortness of breath |
| Other | — | Rapid heart rate, coughing blood, faintness, collapse |
| Urgency | Same day | Emergency, call services |
When is one-sided swelling not ordinary?
Swelling in both legs after surgery is usually ordinary. Swelling clearly worse in one leg, with pain or warmth in the calf, is not something to watch at home. It is examined and usually scanned, because the treatment it may need and the risk it represents are both significant.
What are the signs of a pulmonary embolism?
Sudden shortness of breath, at rest or with very little exertion. Chest pain, often worse on taking a breath. A rapid heart rate, coughing, sometimes coughing blood, and a feeling of dread or faintness. In severe cases, collapse or loss of consciousness.
What should I do?
- Call emergency services or go to the nearest emergency department at once for sudden breathlessness, chest pain on breathing, coughing blood, fainting, or collapse — do not drive yourself.
- Contact the treating team the same day for new one-sided calf pain or swelling, especially with warmth or redness.
- Do not massage the leg, apply heat, or stay still to see whether it settles while a clot is suspected.
Most people who follow instructions on movement, fluids, and compression never develop a clot. Knowing the signs matters because the lung clot leaves very little margin for a delayed decision.
Sources
Internal links
Frequently asked questions
How would I know if I had a clot in my leg, and what should I do?
A deep vein thrombosis usually appears in one leg: the calf swells and aches in a tight, cramping or throbbing way that does not settle with rest, and the skin may look red and feel warm. Contact your treating team the same day, and do not massage the leg or apply heat.
What are the signs that a clot has reached the lungs?
Sudden shortness of breath, which may come on at rest or with very little exertion. Chest pain, often worse on taking a breath. A rapid heart rate, coughing, sometimes coughing blood, and a feeling of dread or faintness. In more severe cases there is collapse or loss of consciousness.
What should I do if I think a clot has reached my lungs?
Call emergency services or go to the nearest emergency department at once for sudden breathlessness, chest pain on breathing, coughing blood, fainting or collapse — and do not drive yourself there. Tell them that you have had recent surgery.
Risks & Limitations
- Most recoveries are uneventful, but a minority of complications are time-critical and are measured in hours rather than days.
- Delay is the main factor that turns a treatable problem into a permanent one, which is why this guide asks you to make contact early rather than to wait and see.
- This guide cannot replace an in-person assessment. It describes general warning signs, not your own case, and it cannot tell you what is happening in your tissue.
- Your own treating team's aftercare instructions take precedence over anything written here. If they differ from this guide, follow your team.
- Some complications described here are rare. Reading about them is not a reason to expect them, and it is not a substitute for asking your team what specifically to watch for.
When to Seek Care
- Difficulty breathing, chest pain, or a swollen and painful calf — call emergency services or attend the nearest emergency department immediately.
- Sudden change or loss of vision — attend the nearest emergency department immediately, and say what procedure you had.
- Severe pain out of proportion to the procedure, or skin turning white, grey, mottled or dusky after an injectable.
- Uncontrolled bleeding, or a flap or graft turning dark or cold.
- Fever, spreading redness, pus or foul-smelling discharge from a wound, or a wound that is opening — contact your treating team the same day, or the hospital main line if the team cannot be reached.
References & Further Reading
- World Health Organization (WHO) — patient safety and emergency care resources
- National Institute for Health and Care Excellence (NICE, UK) — relevant clinical guidance
- American Society of Plastic Surgeons (ASPS) — procedure and safety guidance
- Resuscitation Council — basic life support and emergency response guidance
This page is patient education, not medical advice, and it does not cite individual studies. It cannot diagnose your situation and it does not replace an examination. In an emergency, call emergency services or attend the nearest emergency department. To contact the team at Chongqing West District Hospital, see Contact & Emergency Guidance.