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Primary gain or secondary gain are used in medicine to describe the significant psychological motivators patients may have in reporting symptoms.
Primary gain produces positive internal motivations. For example, a patient might feel guilty about being unable to perform some task. If he has a medical condition justifying his inability, he might not feel so bad. Primary gain can be a component of any disease, but is most dramatically demonstrated in conversion disorder (a psychiatric disorder in which stressors manifest themselves as physical symptoms without organic causes, such as a person who becomes blindly inactive after seeing a murder). The "gain" may not be particularly evident to an outside observer.
Secondary gain can also be a component of any disease, but is an external motivator. If a patient's disease allows him/her to miss work, avoid military duty, obtain financial compensation, obtain drugs, or avoid a jail sentence, these would be examples of secondary gain. These may, but need not be, recognized by the patient. If he/she is deliberately exaggerating symptoms for personal gain, then he/she is malingering. However, secondary gain may simply be an unconscious psychological component of symptoms and other personalities. In the context of a person with a significant mental or psychiatric disability, this effect is sometimes called secondary handicap.[1]
Tertiary gain, a less well-studied process, is when a third party such as a relative or friend is motivated to gain sympathy or other benefits from the illness of the victim.

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