According to a 2004 World Health Organization study, the fourth leading cause of mortality in the world is lower respiratory infections. A huge portion of these infections are labeled as "clinical pneumonia," a lung inflammation that can be contracted by a myriad of causes. Although infants, the elderly and people with compromised immune systems are more likely to succumb to pneumonia, it can strike anyone of any age.
Pathogens that cause clinical pneumonia are inhaled. The respiratory tracts--which include the nose, mouth, throat and lungs--of healthy bodies fight off the germs by filtering them out. However, if a person has been battling a common cold, influenza or bronchitis, the pathogens have a better chance of survival and attack. The most common germ that causes pneumonia in the United States is bacteria, as the primary culprit is streptococcus pneumonia or pneumococcus. Bacterial pneumonia may follow illness, or it can invade healthy lungs without provocation. Viruses cause about a third of reported cases of pneumonia in the United States. Viral pneumonia can become complicated by bacterial pneumonia. Other germs that may cause pneumonia may come from fungi or parasites.
The symptoms of pneumonia are shortness of breath, coughing, chills and fever. If viral pneumonia is present, there may be wheezing. The patient may lack energy and the lips may turn a bluish color. Infected people may even experience nausea.
Many pneumonia infections can be heard as crackling, bubbling or dull thud sounds through a stethoscope. Patient history is considered. If symptoms of pneumonia are present, a chest X-ray is usually ordered. Blood and sputum tests may be able to determine the pathogen responsible for the illness. Invasive diagnostic tests are usually only performed if the patient is not responding to treatment or has life-threatening complications.
Pneumonia is typically treated with antibiotics, and only the most severe or unstable patients are hospitalized. (If the patient is hospitalized, the antibiotic treatment may be given intravenously.) Pain reliever may be prescribed or recommended. Chest therapy may also be performed.
The best preventive action for pneumonia is the practice of good hygiene. Many cases of clinical pneumonia are caused by direct contact with people who have the infection. Environmental factors that may cause pneumonia, such as parasites, fungi and other germs, should be eradicated or made inaccessible to healthy lungs where possible. Flu shots and pneumonia vaccines may also lessen the incidences of pneumonia.