Pneumonia

Before the development of antibiotics pneumonia was the leading cause of death in the United States. It still is a dangerous disease causing the deaths of over 64,000 people each year.

Pneumonia is an acute infection of the lung parenchyma, alveolar spaces and interstitial tissues causing consolidation. What this definition is saying is that pneumonia is an infection of the functional parts of the lungs causing the lung tissue to contract in on itself. The lung tissue that is infected has a harder time transferring oxygen to the bloodstream causing the increased shortness of breath associated with this condition. Other symptoms of pneumonia include cough, fever, chest pain, shortness of breath, tachycardia or an increase in the heart rate over what is normal, tachypnea or a rapid respiratory rate, a productive cough or a cough producing sputum and a feeling of malaise.

Different things may cause pneumonia. Virus, funguses, and parasites can cause it. The major cause of pneumonia is bacteria.

Source - NCHS Faststats - Pneumonia