Hypersensitivity, in emotions, is the state of being too sensitive to criticism of other people's attitudes. For example, someone who blows up at a friend for a minor critique could be said to be hypersensitive to criticism. Biologically, hypersensitivity refers to having an extreme physical sensitivity to a substance or condition. For instance, some people have severe reactions to some medications, sprays, perfumes, or chemicals that don't bother most other people. This can be referred to as "hypersensitivity."