<unk>  is an illness of the lungs and respiratory system in which the alveoli (microscopic air-filled sacs of the lung responsible for absorbing oxygen from the atmosphere) become inflamed and flooded with fluid.<unk>  can result from a variety of causes, including infection with bacteria, viruses, fungi, parasites, and chemical or physical injury to the lungs. Typical symptoms associated with<unk>  include cough, chest pain, fever, and difficulty in breathing. Diagnostic tools include x-rays and an examination of the sputum. Treatment depends on the cause of<unk> ; bacterial<unk>  is treated with antibiotics.<unk>  is a common illness which occurs in all age groups, and is a leading cause of death among the elderly and people who are chronically and terminally ill. Vaccines to prevent certain types of<unk>  are available. The prognosis depends on the type of<unk> , the appropriate treatment, any complications, and the person's underlying health.
Pneumonia
Aspiration pneumonia
Bacterial pneumonia
Pneumonitis
Atypical pneumonia
Viral pneumonia
Fungal pneumonia
Community-acquired pneumonia