Caffeine intoxication is a syndrome that results from the consumption of an excessive amount of caffeine and manifests as adverse psychological and physical symptoms. Caffeine intoxication is recognized as a diagnosis in both the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), and the World Health Organization’s International Statistical Classification of Diseases and Related Health Problems, 10th Revision (ICD-10).

A diagnosis of caffeine intoxication is defined by recent caffeine consumption and experiencing five or more intoxication symptoms resulting in clinically significant distress or functional impairment (e.g., unable to work). Symptoms of caffeine intoxication include, but are not limited to, restlessness, anxiety, sleeplessness, flushed face, sweating, gastrointestinal problems, muscle twitches, pressured speech, heart disturbances, and agitation. Other symptoms that have been observed include fever, sensory ...