"U.S. researchers say they have found clear signs that blood clots in the lungs are being overdiagnosed exposing patients to potentially dangerous side effects from unnecessary drugs.  Using national data the researchers found the rate of socalled pulmonary embolisms or PEs nearly doubled with the introduction of a new powerful diagnostic test more than a decade ago.  Yet there was only a slight drop in deaths from the condition over the same period suggesting many of the clots were too small to cause harm.  Rather than an epidemic of disease we think the increased incidence of PE reflects an epidemic of diagnostic testing that has created overdiagnosis the researchers write in the Archives of Internal Medicine.  Its been estimated that more than  Americans have a pulmonary embolism each year. The condition usually occurs when a blood clot travels from the legs to the lungs sometimes with fatal results.  But with increasingly sophisticated tools doctors may be spotting clots that would never have been fatal in the first place.  One such tool is called a CT chest scan which produces detailed images with highdose xrays and is being used in millions of patients every year in the U.S.  In the years before  when the technique was introduced  per  Americans were diagnosed with a pulmonary embolism annually. After  that number rose to  per .  The number of deaths caused by the condition dropped only little however from . per  in  to . per  in .   This is consistent with overdiagnosis of pulmonary embolisms that may have caused very little harm may not have caused death said Dr. Renda Soylemez Wiener of Boston University who worked on the study.  On the other hand the bloodthinning drugs used to treat blood clots increase the risk of bleeding in the brain or gastrointestinal tract for example.  According to the new results such complications rose from three to five per  people hospitalized with PE per year after doctors began using chest CT scans.  The new findings add to other evidence showing that medical testing is on the rise across the U.S. although in many cases the impact on overall health remains unclear.  CT scans expose patients to radiation for example which can increase the likelihood of developing cancer. And the dyes used to enhance the scan also cause kidney damage in a significant portion of people.  I think doctors should think carefully about the pretest probability of a pulmonary embolism before they order this test Wiener told Reuters Health.  Yet there is no easy solution at this point because untreated blood clots can be fatal she added.  Right now it is a difficult place for the patient to be in Wiener said.  SOURCE bit.lymmZKK httpbit.lymmZKK Archives of Internal Medicine online May  . Our StandardsThe Thomson Reuters Trust Principles. httpthomsonreuters.comenaboutustrustprinciples.html"