Final answer:
When a clot known as thrombus breaks loose and circulates through the bloodstream, it is called an embolus. This can lead to an embolism, a serious blockage in the body.
Step-by-step explanation:
When a clot forms within an undamaged or only slightly damaged blood vessel, this condition is known as thrombosis, which can lead to a thrombus lodging within a vessel and impeding the flow of blood. If part of the thrombus becomes dislodged, it is then called an embolus. An embolus that travels through the bloodstream and causes a blockage elsewhere is referred to as an embolism, which can result in serious medical conditions such as a stroke, a heart attack, or a pulmonary embolism when it obstructs a critical blood vessel.