The affection, viral illness transmitted by a mosquito, comes very acometendo a high number of the Brazilian and world-wide population. However, it is questioned: how can the population fight the affection without taking knowledge of its characteristics? How those that do not know which the measures that must take to fight the illness can make it? How to recognize its symptoms if these are similar to the ones of as much other illnesses? Being thus, the present research (intitled Affection: one badly that it needs to be known to be fought) presents a thematic one of excellent social importance, therefore it intends to guide the readers on the risk of the way affection, to acquire knowledge them on the attitudes to be taken so that the incidence of this illness can diminish. Thus, necessary information on the symptoms will be taken, form of infect, prevention and treatment of this illness to that they have the chance of if appropriating of the content of this writing, so that thus its combat is possible. The affection incidence in Brazil and the world it comes increasing in elapsing of last the five decades, therefore the concern of the governing and the population related to this problem that can lead to the death, also must increase. In Brazil, specifically, the concern must be redoubled, therefore according to information of the OMS (World-wide Organization of Health), our country answered almost for two teros of the cases of affection in Americas in 2007. Of this form, the present research was developed by considering extremely important the quarrel on the affection, for believing that possible solutions to fight this badly can be taken by the population in the day the day and by the governing in its projects of action, especially for the sector of the governments (municipal, state and federal) responsible for the maintenance of the public health.