Diagnosis:

To diagnose pneumonia, the doctor begins with a medical history and physical examination. By placing a stethoscope on the chest, the doctor may be able to hear crackling sounds, coarse breathing, wheezing and/or the breathing may be faint in a particular area of the chest. Additionally, the doctor may order a chest x-ray, a sputum gram stain and a blood test. The chest x-ray may show a blotchy-white area, where fluid and pus has accumulated in the lung's air sacs. The sputum grain stain and the blood test may determine the cause and severity of the condition.

A positive blood test for cold-hemagglutinins in 50-70% of patients after 10 days of infection (cold-hemagglutinin-test should be used with caution or not at all since 50% of the tests are false-positive), lack of bacteria in a gram-stained sputum sample, and a lack of growth on blood agar. Mycoplasma atypical pneumonia can be complicated by Stevens-Johnson syndrome, hemolytic anemia, encephalitis or Guillain-Barré syndrome.

Other serology tests include complement fixation which detects both IgG and IgM specific to M.pneumoniae, enzyme-linked immunoassay for M. pneumonia specific IgM, and indirect hemagglutination. All of these have acceptable sensitivity and specificity.