Pneumonia is an inflammatory lung condition affecting the air sacs (alveoli) associated with fever, chest symptoms, and lack of air space on an X-ray. It is typically caused by an infection by bacteria, viruses, fungi, or parasites through inhalation or aspiration. Symptoms include cough, fever, chills, and difficulty breathing. While transmission methods are unknown, organisms can be spread through respiratory secretions. Control methods include vaccination to prevent common causes, avoiding sick individuals, smoking cessation, and frequent handwashing.