Palpating the chest as it expands and tapping the chest wall to identify dull, non-resonant areas can identify stiffness and fluid, signs of CAP. Listening to the lungs with a stethoscope (auscultation) can also reveal signs associated with CAP. A lack of normal breath sounds or the presence of crackles can indicate fluid consolidation. Increased vibration of the chest when speaking, known as tactile fremitus, and increased volume of whispered speech during auscultation can also indicate the presence of fluid.Several tests can identify the cause of CAP. Blood cultures can isolate bacteria or fungi in the bloodstream. Sputum Gram staining and culture can also reveal the causative microorganism. In severe cases, bronchoscopy can collect fluid for culture. Special tests, such as urinalysis, can be performed if an uncommon microorganism is suspected. Chest X-rays and X-ray computed tomography (CT) can reveal areas of opacity (seen as white), indicating consolidation. CAP does not always appear on x-rays, sometimes because the disease is in its initial stages or involves a part of the lung not clearly visible on x-ray. In some cases, chest CT can reveal pneumonia not seen on x-rays. However, congestive heart failure or other types of lung damage can mimic CAP on x-ray.When signs of pneumonia are discovered during evaluation, chest X-rays and examination of the blood and sputum for infectious microorganisms may be done to support a diagnosis of CAP. The diagnostic tools employed will depend on the severity of illness, local practices and concern about complications of the infection.
In children, most deaths (over two million a year) occur in the newborn period. According to a World Health Organization estimate, one in three newborn deaths result from pneumonia. Mortality decreases with age until late adulthood, with the elderly at risk for CAP and its associated mortality. More CAP cases occur during the winter than at other times of the year. CAP is more common in males than females, and more common in black people than Caucasians. Patients with underlying illnesses (such as Alzheimers disease, cystic fibrosis, COPD, tobacco smoking, alcoholism or immune-system problems) have an increased risk of developing pneumonia. See also
Bacterial pneumonia
Viral pneumonia
Fungal pneumonia
Parasitic pneumonia

References
Mandell LA, Wunderink RG, Anzueto A,  et al. (March 2007). "Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults". Clinical Infectious Diseases. 44 (Suppl 2): S27–72. doi:10.1086/511159. PMID 17278083. External links
Infectious Diseases Society of America/American Thoracic Society Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults PDF