Printer Friendly VersionEmail A FriendAdd ThisIncrease Text SizeDecrease Text Size

Blood clots



Blood clots are the clumps that occur when the blood hardens from a liquid to a solid (coagulates). A blood clot that forms inside a blood vessel or within the heart and remains there is called a thrombus.

A thrombus that travels from the blood vessel or heart to another location in the body is called an embolus. The disorder is called an embolism. For example, an embolus that occurs in the lungs is called a pulmonary embolism.

Sometimes other materials can act like an embolus and block blood flow, including:

See also:

Alternative Names

Clot; Emboli; Thrombi



Signs and tests

Support Groups

Expectations (prognosis)

Calling your health care provider


Thrombi and emboli can firmly attach to a blood vessel. They can partially or completely block the flow of blood in that vessel.

A blockage in the blood vessel prevents normal blood flow and oxygen from reaching the tissues in that location. This is called ischemia. If ischemia is not treated promptly, it can result in tissue damage, or death of the tissues in that area.



Review Date: 6/10/2008
Reviewed By: Sean O. Stitham, MD, private practice in Internal Medicine, Seattle, Washington; and James R. Mason, MD, Oncologist, Director, Blood and Marrow Transplantation Program and Stem Cell Processing Lab, Scripps Clinic, Torrey Pines, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission ( URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- 2009 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

Home Page
Why Choose Us
Website Terms of Use

Visitor & Patient Info
Patient Portal
We Speak Your Language
Patient Privacy
Contact Us

Find a Physician
Medical Services
Maimonides In the News
Directions & Parking

Medical Education
Career Opportunities
Nurses & Physicians
Staff Intranet Access
Maimonides Medical Center    |    4802 Tenth Avenue    |    Brooklyn, NY 11219    |    718.283.6000    |