Fayrasyada waxay gaadhi karaan sambabada iyada oo loo marayo dhowr waddooyin kala duwan. Fayrasyada neefsashada ee neefsashada ayaa sida caadiga ah la qaadaa marka dadku taabtaan walxaha wasakhaysan ka dibna waxay taabtaan indhahooda ama sanka. Cudurrada kale ee fayrasku waxay dhacaan marka dhibcaha hawada ee wasakhaysan ay neefsadaan afka ama sanka. Marka ay maraan hawo-mareenka sare, fayrasyadu waxay gali karaan sambabada, halkaas oo ay ku soo duulaan unugyada huwan hawo-mareenka, alveoli, ama parenchyma sambabada. Fayrasyada qaarkood sida jadeecada iyo herpes simplex waxay ku gaari karaan sambabada dhiigga.
Fayrasku wuxuu gaadhi karaa sambabada