It may be of natural origin (pathological), in which sense it is also called embolism, for example a pulmonary embolism; or it may be artificially induced (therapeutic), as a hemostatic treatment for bleeding or as a treatment for some types of cancer by deliberately blocking blood vessels to starve the tumor cells.

When the embolus bears a radiopharmaceutical for unsealed source radiotherapy, the process is called radioembolization or selective internal radiation therapy (SIRT).

Embolization is used to treat a wide variety of conditions affecting different organs of the human body.

[8] The purpose is to prevent blood flow to an area of the body, which can effectively shrink a tumor or block an aneurysm.

The position of the correct artery or vein supplying the pathology in question is located by digital subtraction angiography (DSA).

These images are then used as a map for the radiologist to gain access to the correct vessel by selecting an appropriate catheter and or wire, depending on the 'shape' of the surrounding anatomy.