Health Information Library

Blood that becomes thick or clumped and clogs a blood vessel.

Thrombosis happens when a clump of blood clogs a blood vessel. This can restrict blood flow and cause a life-threatening stroke, heart attack or blockage of blood to the lungs. It can be caused by blood vessel diseases, surgery, hormone treatments, pregnancy, other medical conditions or lack of movement in the body.

Symptoms depend on the location and size of the blood clot.

Treatments include a variety of medicines, such as aspirin and blood thinners, or a clot-catching filter inserted into a blood vessel.