Washington, Jul 5 (IANS): Something as simple as sitting for long periods in one posture daily is fraught with grave risks, especially for women.

Such women are two to three times more likely to develop a life-threatening blood clot in their lungs than more active women, according to a new study.

This is the first study to prove that a sedentary lifestyle increases your risk of developing a pulmonary embolism - a common cause of heart disease.

Pulmonary embolism develops when part, or all, of the blood clot travels through the bloodstream from the deep veins in the leg and up into the lungs. Symptoms include difficulty in breathing, chest pain and coughing, reports the British Medical Journal.

While other studies have explored the relationship between physical activity and pulmonary embolism, few data are available linking the condition with physical inactivity.

Christopher Kabrhel, of the department of emergency medicine at Massachusetts General Hospital, and colleagues studied 69,950 female nurses over an 18-year period providing detailed information about their lifestyle habits by completing biennial questionnaires.

They found that the risk of pulmonary embolism is more than two times higher in women who spend most time sitting (more than 41 hours a week outside of work) compared with those who spend least time sitting (less than 10 hours a week outside of work), according to a Massachusetts statement.

The results remained conclusive after taking account of factors such as age, body mass index and smoking, adding to the evidence that physical inactivity is a major cause of this condition.

The study also shows that physical inactivity correlated with heart disease and hypertension could be one of the hidden mechanisms that link arterial disease and venous disease.