Patients often present with an apparent acute psychosis that is secondary to an organic (medical) rather than a functional (psychiatric) etiology. Distinguishing the two can be difficult. Factors that suggest an organic etiology include disorientation, age of onset older than 35 years, visual hallucinations, lethargy, altered level of consciousness, and abnormal vital signs. Other factors that indicate a psychosis due to an organic etiology include tremor, ataxia, aphasia, occasional periods of perception or lucidity, sudden onset of symptoms, emotional lability, social immodesty, and an abnormal physical examination. Psychiatric patients, on the other hand, tend to be awake and alert, with appropriate orientation to time, place, and person. They will typically have normal vital signs. They demonstrate social modesty, intelligible speech, flat affect, auditory hallucinations, and a gradual onset of their symptoms.