lung and airway disorders
Overview of Pneumonia
Causes of Pneumonia
Pneumonia is caused by different microorganisms—including Overview of Bacteria , The Overview of the Respiratory System are constantly exposed to microorganisms. The nose and throat are full of bacteria and sometimes viruses, and people regularly inhale from the air or aspirate from the digestive tract, mouth, or throat small amounts of these organisms. Normally these organisms are readily dealt with by the The cough reflex, which helps expel mucus and foreign substances The cells lining the lung passageways, which prevent microorganisms from invading the lungs and which push mucus and foreign substances upward so that they can be coughed out Proteins made by lung cells, which attack microorganisms White blood cells within the lungs, which are part of the normal immune system and which also attack microorganisms Pneumonia develops when Defense mechanisms are not functioning correctly. A large amount of bacteria is inhaled and overwhelms normal defenses. A particularly infective organism is introduced. Usually pneumonia starts after microorganisms are inhaled (aspirated) from the upper airways into the lungs, but sometimes the infection is caused by an imbalance in the microorganisms in the airways and lungs or by microorganisms that are inhaled from the air, carried to the lungs by the bloodstream, or invade the lungs directly from a nearby site of infection. Where people are when pneumonia develops is important because different organisms tend to be present in different settings. Organisms in some settings, such as hospitals, are typically more dangerous and more commonly resistant to antibiotics than organisms present in other settings. Also, people in some settings are more likely to have disorders that make them more likely to develop pneumonia. Some categories of pneumonia include Community-Acquired Pneumonia , Hospital-Acquired Pneumonia , Health care–associated pneumonia, which is an infection acquired in a health care setting other than the hospital, such as a nursing home or dialysis center, is considered a subset of community-acquired pneumonia because these people are likely to have pneumonia that is caused by the same organisms that are likely to infect other people living in the community . Other categories of pneumonia include Aspiration Pneumonia and Chemical Pneumonitis , Obstructive pneumonia,which occurs when a blockage of the air passages in the lungs (such as caused by a tumor) causes bacteria to accumulate behind the blockage is a nonmedical term used to describe a mild case of Community-Acquired Pneumonia that does not require bedrest or hospitalization. Some people might even feel well enough to go to work and participate in other daily activities. Pneumonia may occur after surgery, particularly abdominal surgery, or after an injury (trauma), particularly a chest injury, because the pain of those conditions keeps people from breathing deeply and from coughing. If people do not breathe deeply and cough, microorganisms are more likely to remain in the lungs and cause infection. Other people who do not breathe deeply and cough include those who are debilitated, bedridden, paralyzed, or unconscious. Such people are also at risk of pneumonia. Another critical feature is whether the pneumonia occurs in a healthy person or in someone who has an Pneumonia in Immunocompromised People . A person who has an impaired immune system is far more likely to contract pneumonia, including pneumonia caused by unusual bacteria and viruses and even fungi or parasites. Also, a person whose immune system is impaired may not respond as well to treatment as someone whose immune system is healthy. People who may have an impaired immune system include those who Are being treated with certain drugs (such as corticosteroids or chemotherapy drugs) Have certain diseases, such as acquired immunodeficiency syndrome (AIDS) or various types of cancer Have an undeveloped immune system, as is the case of infants and toddlers Have an immune system that is impaired by severe illness Other conditions that predispose people to pneumonia include alcohol use disorder, Smoking and Other Tobacco Use and vaping, 