Conversion disorder, also called functional neurological symptom disorder, is an illness of one or more symptoms that affect voluntary motor functions (e.g., breathing or walking) or sensory functions (e.g., touch, pressure, temperature, pain.)

A diagnosis of conversion disorder requires the following factors:

• There is a mismatch between the symptom(s) and any recognized neurological or medical conditions the individual may have.
• The symptoms are not better explained by another medical or mental disorder.
• The symptoms cause significant distress or impairment in social, occupational, or other important areas of functioning or warrants medical evaluation.

A diagnosis of conversion order may be specified with any of the following symptom types:

• With weakness or paralysis
• With abnormal movement (e.g., tremor, dystonic movement, involuntary muscle movements, gait disorder)
• With swallowing problems
• With speech problems
• With attacks or seizures
• With anesthesia or sensory loss
• With special sensory symptom (e.g., visual, olfactory, of hearing problem)
• With mixed symptoms