Women sitting down for the majority of the day are more likely to develop a deadly blood clot in their lungs than active women.
A new study published on the British Medical Journal website, finds their risk is increased by two to three times.
A life threatening pulmonary embolism develops when all or part of a blood clot travels through the bloodstream to the lungs.
Symptoms include difficulty breathing, chest pain and coughing.
A total of 69,950 female nurses took part in the Canadian based study during an 18-year period.
Researchers found the higher risk is faced by women who sit for longer than 41 hours a week outside of their working hours.