Pneumonia can be caused by typical or atypical bacteria. Mycoplasma pneumoniae typically causes lower lobe involvement in young patients and presents with mild symptoms. Chlamydia pneumoniae causes a slow recovery with sore throat and hoarseness. Legionella pneumophila is associated with fresh water and moist soil exposure and can cause extrapulmonary findings on labs. Investigations for atypical pneumonia include CBC, chest x-ray, sputum examination, blood cultures, and PCR or cultures of sputum.