[The oncologic patient: nursing care based on physiopathologic knowledge].
The patient with cancer is affected both by the development of the neoplasia and by the toxic action of radiotherapy and chemotherapy, often used at aggressive therapeutic intervals to eradicate tumourous cells. The most serious physiological consequences are the occurrence of gaseous exchange within tissues, the risk of infection and haemorrhage, the change in levels of nutrition and evacuation, the deterioration in tissue structure and oral mucous and the change in sleeping patterns and sense of well-being. As far as psychological, social and emotional problems are concerned, the main difficulties which occur are a sense of anxiety and fear and a change in one's self-image. The present article explains what are the main factors involved in producing the changes in the situations mentioned above and the physiopathological mechanisms underlying them, an understanding of which is essential both to prevent them from occurring and to provide the proper nursing care. Finally, it explains what information should be given to a patient and/or his family in order to help him re-integrate back into his normal environment in periods of remission.