According to a new study, pulmonary embolism [blood clots in the lungs] may be caused by excessive sitting, WebMD reports.
The study of nearly 70,000 nurses who were monitored for 18 years found that those who spent their leisure time sitting or being sedentary were far more likely to suffer from pulmonary embolism than those who were more active.
That risk remained even after researchers took into account other factors, including body weight, smoking, heart disease and the use of medications such as blood thinners and NSAIDs.
"Women who sat the most had more than twice the risk of PE compared to women who sat the least," study researcher Dr. Christopher Kabrhel told WebMD.
Although pulmonary embolism can be treated, it can also be fatal. Researchers, therefore, say the condition needs to be taken seriously, WebMD notes.
"It's the third most common cause of cardiovascular death in the country. It's about as common as strokes," Kabrhel said to WebMD.
The study wasn’t able to definitively prove that the nurses developed pulmonary embolism due to prolonged sitting, but experts say that sluggish blood flow, particularly in the legs, does contribute to the problem, WebMD reports. Part of a clot in a deep vein in the leg can break off and travel to the lungs, resulting in pulmonary embolism.
"Vein blood clots do occur in people who are not very mobile," Dr. James D. Douketis, said to WebMD. "The extreme example is someone who's had a stroke and is paralyzed. The risk of having a blood clot there is one in two."
In contrast, prolonged sitting increases the annual risk of having a pulmonary embolism from one or two out of every 1,000 adults to one or two in every 500 adults.
