Sickness behavior

Sickness behavior is a coordinated set of adaptive behavioral changes that develop in ill individuals during the course of an infection. They usually (but not necessarily) accompany fever and aid survival. Such illness responses include lethargy, depression, anxiety, loss of appetite, sleepiness, hyperalgesia, reduction in grooming and failure to concentrate. Sickness behavior is a motivational state that reorganizes the organism's priorities to cope with infectious pathogens. It has been suggested as relevant to understanding depression, and some aspects of the suffering that occurs in cancer.