Tonsils: Small masses of lymphoid tissue on either side of the throat.
Streptococcus: The most common disease-causing bacteria in humans, which can be treated with antibiotics. If left untreated, some types of streptococcal bacteria may give rise to more serious diseases.
Pneumonia: An inflammatory infection that occurs in the lung.
Bronchitis: Inflammation (swelling and reddening) of the bronchi.