Pneumoniais a serious infection or inflammation of one or both lungs.
Description of Pneumonia
Pneumoniais caused by the inhalation of infected microorganisms (tiny, single-celled livingorganisms, such as bacteria, viruses, fungi or protozoa) spread through contact with an infected person. The microorganisms enter the body through the mouth, nose and eyes. If the body'sresistance is down, the natural process of fighting off diseases is weakened and themicroorganisms are free to spread into the lungs and the lungs' air sacs. The air sacs becomefilled with fluid and pus from the infectious agent, making it more difficult for the body to getthe oxygen it needs, and the person may become sick.Potential complications of pneumonia include pleural effusion (fluid around the lung), empyema(pus in the pleural cavity), hyponatremia (low blood sodium) and rarely, anabscessin the lung.
Causes of Pneumonia
There are over 30 different causes of pneumonia, but the most common causes are bacteria(including mycoplasma) and viruses. Corresponding to these causes are the most common typesof pneumonia - bacterial pneumonia, viral pneumonia and mycoplasma pneumonia.
Pneumonia-causing bacteria is present in many throats, but when the body's defenses areweakened (for example, by illness, old age, malnutrition or impaired immunity) the bacteria canmultiply, working its way into the lungs, inflaming the air sacs and filling the lungs with liquidand pus. The bacteria that cause bacterial pneumonia are streptococcus pneumonia (resulting inlobar pneumonia), hemophilusinfluenza(resulting in bronchopneumonia), legionella pneumophilia (resulting inLegionnaires' disease) and staphylococcus aureus.
Half of all pneumonias are believed to be caused by viruses, such as influenza (flu), adenovirus,coxsackievirus, chickenpox,measles, cytomegalovirus andrespiratory syncytial virus. These
viruses invade the lungs and multiply.
Mycoplasmal pneumonia (also called "walking pneumonia")
Similar to bacterial pneumonia, the mycoplasmas multiply and spread, causing infection.