Patients often quote diseases or illnesses that either do not exist per se or are hard to prove that they exist. Often symptoms are vague and, therefore, difficult for patients to qualify in a language clinicians can understand, interpret and act upon. Physicians often perpetuate this by giving 'diagnoses of exclusion', or using poor explanations, oversimplifications, conflicting diagnostic criteria or vague historical terms that have now evolved into something else. However, the history taker must be able to interpret the subtle language barrier that exists between doctor and patient. In this short review of the literature, some commonly quoted conditions are examined more closely to try and understand further the terminology used by both patients and clinicians alike.