Abnormal means not normal. For example, the man to the right
is abnormally tall. Something that is abnormal differs in some
way from the normal state, condition, rule, or structure.  The
term is typically used to refer to something that is unusual in a
negative direction (e.g., very low intelligence) rather than in a
positive direction (e.g., very high intelligence) although both are
technically abnormal. Abnormality refers to the state or quality
of being abnormal or something that is different from usual or
formed improperly, such as an impairment or dysfunction. In
medicine, abnormal is often used to refer to blood test results
that are outside the reference range (normal range), which can
indicate the presence of an abnormality (e.g., sickness,
disease) in the body.
FEATURED BOOK: Abnormal Psychology by Ron Comer

Diagnostic imaging techniques, such as x-rays, are used to detect abnormalities in bodily
structure (such as a bone break) whereas other imaging techniques (and non-imaging
procedures) can evaluate abnormalities in bodily function.In mental health, one of the
most popular topics is abnormal psychology, which refers to abnormal psychological
conditions such as major depressive disorder or psychotic disorders (the latter of which
is characterized by being detached from reality). Abnormal is similar to the word
aberration. Abnormal comes the Latin word "ab" meaning "away from," and the Latin word
"norma" meaning "rule." Put the words together and you have "away from rule."

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