People who have surgery are 70 times more likely to be re-admitted to hospital with a blood clot within six weeks of leaving than patients who did not need an operation, research shows.
University of Oxford researchers said this meant the risk of suffering a potentially fatal blood clot after surgery was higher than previously thought.
They said operations for hip and knee replacements and cancer surgery made people particularly vulnerable.
A study of more than 947,000 British women also showed people were 10 times more likely to be admitted with a clot if they had their operation as a day-case when compared with those not having surgery at all.
The risk was highest in the third week after an operation.
The study estimates that one in 140 middle-aged women having inpatient surgery will be admitted with a blood clot in the 12 weeks after surgery.
One in 45 will suffer a clot after a hip or knee replacement and one in 85 after cancer surgery, the research in the online British Medical Journal estimated.
The authors said: “These findings suggest that the risk of venous thromboembolism after surgery is greater and lasts for longer than previously thought.”
Copyright Press Association 2009