What is an allergy?

Allergy is the result of the immune system overreacting to harmless stimuli in the environment.

Examples of stimuli or 'allergens' include pollen, dust, eggs and milk.

The body recognises these harmless allergens as foreign, which leads to white blood cells releasing antibodies.

Antibodies then trigger mast cells (another form of immune cell) to produce histamine and this promotes inflammation. You may have seen how inflammation manifests in your own body following injury or infection. Typically the inflamed part of the body becomes hot, red, swollen and very painful.

SK
Answered by Saadiyah K. Biology tutor

4632 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

Can you explain the oxygen dissociation curve.


In a population of deer there are two alleles, p and q. Individuals with allele p are faster than those with allele q and so are better at avoiding predation by wolves. Explain how natural selection will affect the characteristics of the deer population.


Explain the differences between aerobic and anerobic respiration in terms of the roles of co-enzymes


Briefly describe the bonding between Adenine and Thymine units (1)


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning