One term that is used is antigen. An antiGEN will GENerate an ANTIbody which will 'kill' the antigen.
antigen- any substance the body regards as foreign
antigen
If it can be harmful, it can be referred to as pathogen.
A foreign substance is a substance that doesn't belong somewhere. A piece of glass or splinter is a foreign substance that people get in their body.
A foreign substance is a substance that doesn't belong somewhere. A piece of glass or splinter is a foreign substance that people get in their body.
The substance that the body regards as foreign, which includes viruses, bacteria, toxins, and transplanted organs, is called an "antigen." Antigens trigger an immune response, as the immune system identifies them as potentially harmful invaders. This response can lead to the production of antibodies and activation of immune cells to eliminate the threat.
antigen
pathogen
An antibody is a substance formed by the body in response to a perceived foreign substance. Antibodies are produced by the immune system to help identify and neutralize potentially harmful invaders, such as bacteria and viruses.
The body can reject implants and, of course, blood if it's not your own type or O negative (I think). You can look at allergies the same way - hay fever, nuts, strawberries - the body detects them as harmful even though they are harmless.
Antigenan·ti·gen/ˈantijən/Noun:A toxin or other foreign substance that induces an immune response in the body, esp. the production of antibodies.
A foreign substance is any material that is not naturally present in a certain environment or body. It can come from outside sources and may cause harm, contamination, or interference with normal processes.