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.

Answered by Saadiyah K. Biology tutor

3705 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

Some substances can cross the cell-surface membrane of a cell by simple diffusion through the phospholipid bilayer. Describe other ways by which substances cross this membrane.


What are enzymes and how do they work?


What is the equation for photosynthesis?


What is transcription and how does it differ in eukaryotes and prokaryotes


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo
Cookie Preferences