Pneumonia, for example, is generally confined to one or both lungs but can become disseminated through sepsis, in which the microorganism responsible for the pneumonia "seeds" the bloodstream or lymphatic system and is transported to distant sites in the body.
Pneumonia primarily affects the lungs but can be disseminated via sepsis, which allows the causative agent to spread throughout the body via the bloodstream or lymphatic system to distant areas.