Blood Clots

Despite the best efforts of clinicians, some patients develop deadly blood clots known as venous thromboembolisms (VTEs). Also known as deep vein thrombosis (DVT), a VTE is a blood clot that forms in the deep veins of the legs, arms, or pelvis. If the clot dislodges and travels to the lung, it is called a pulmonary embolism. While anyone may develop a dangerous blood clot, hospital patients are often at higher risk because of their underlying condition, recent surgery, or immobility.

AHRQ's efforts to prevent and treat blood clots are reflected in the following tools, research, and resources.

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Preventing Hospital-Associated Venous Thromboembolism: A Guide for Effective Quality Improvement
Pulmonary embolism resulting from DVT is the most common preventable cause of hospital death. Pharmacologic methods to prevent VTEs are safe, effective, and cost-effective but are significantly underused. This guide assists quality improvement practitioners in leading an effort to improve prevention of hospital-acquired VTE. An impact case study shows how New York hospitals and New Mexico hospitals used the AHRQ guide to revise their protocols for preventing blood clots.

Your Guide to Preventing and Treating Blood Clots
This guide for patients describes ways to prevent and treat blood clots. It also describes symptoms and medication side effects, as well as when to go to the emergency room.

Blood Thinner Pills: Your Guide to Using Them Safely
AHRQ offers a free booklet and video about blood thinner medicines. Staying Active and Healthy with Blood Thinners, a 10-minute video, features easy-to-understand explanations of how blood thinners work and why it is important to take them correctly. Blood Thinner Pills: Your Guide to Using Them Safely, a 24-page booklet in English and Spanish, explains how these pills can help prevent dangerous blood clots from forming and what to expect when taking these medicines.


AHRQ's Patient Safety Network features studies on blood clots, ranging from a pediatric central line clot to a popular blood-thinner drug causing deaths and injuries in nursing homes. Studies on venous thromboembolism range from venous thromboembolism after trauma and use of multidisciplinary rounds for venous thromboembolism prevention to postsurgical pulmonary embolism.


AHRQ Evidence Report Compares Risks and Benefits of Blood Clot Prevention Approaches
This report compares the effectiveness of strategies to prevent venous thromboembolism for people getting hip or knee replacements and people being treated for hip fractures.

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