Blood clots deep in the veins are among the leading causes of death in the U.S. They are called deep vein thromboses or DVTs. When a blood clot breaks loose and lands in the lungs it is called a pulmonary embolism and can be a life-threatening event.
A large new study from Denmark shows that people who start taking oral corticosteroids such as prednisone triple their risk for such blood clots. Ongoing use doubles the risk.
New use of inhaled steroids for conditions such as asthma or COPD can also boost the chance of developing a deep vein clot and a resulting pulmonary embolism. (There is no information in this study on nasal steroids such as those used for allergies.) Although such drugs have utility, we continue to learn about potentially serious side effects of cortisone-like drugs.