Hysteria, a mental disorder arising from an unconscious emotional conflict. Persons suffering from this type of mental illness disguise their emotional problems even from themselves and involuntarily develop symptoms to protect themselves from facing these problems.
In conversion-type hysteria the person develops physical symptoms. These take almost any form: digestive troubles; pain and fever; convulsions; paralysis; or temporary blindness or deafness. In dissociative-type hysteria, alterations in the person's state of consciousness or identity occur. Symptoms include amnesia, sleepwalking, or the development of multiple personalities.
The symptoms of both types are emotionally based rather than being due to organic disease. Treatment is provided by psychiatric techniques, and consists of helping the patients understand and face their real problems.