An excessive or abnormal sensitivity to a substance.

What does hypersensitivity mean?

Hypersensitivity (also called hypersensitivity reaction or intolerance) refers to undesirable reactions produced by the normal immune system, including allergies and autoimmunity. ...

Where did the word hypersensitive come from?

hypersensitive (adj.)

1827, a hybrid from hyper- "over, exceedingly, to excess" + sensitive.