What is pneumonia?
Pneumonia is an infection of one or both lungs which is usually caused by a bacteria, virus, or fungus. Prior to the discovery of antibiotics, one third of all people who developed pneumonia subsequently died from the infection.
How do people "catch pneumonia?"
Most cases of pneumonia are contracted by breathing in small droplets that contain the bacteria or virus that can cause pneumonia. These droplets get into the air when a person infected with these germs coughs or sneezes. In other cases, pneumonia is caused when bacteria or viruses that are normally present in the mouth, throat, or nose inadvertently enter the lung. During sleep it is quite common for people to aspirate secretions from the mouth, throat, or nose.
Normally, the body's reflex response (coughing back up the secretions) and immune system will prevent a pneumonia from starting. However, if a person is in a weakened condition from another illness, a severe pneumonia can develop. People with emphysema, heart disease, and swallowing problems, as well as alcoholics, drug users and those who have suffered a stroke or seizure are at higher risk for developing pneumonia.
Once the bacteria, virus or fungus enter the lungs, they usually settle in the air sacs of the lung where they rapidly grow in number. This area of the lung then becomes filled with fluid and pus as the body attempts to fight off the infection.
What are the symptoms of pneumonia?
Most people who develop pneumonia initially have symptoms of a cold which is then followed by a high fever (sometimes as high as 104 degrees), shaking chills, and a cough with sputum production. The sputum is often bloody. Chest pain may develop on one side and the patient may become short of breath. In other cases of pneumonia, there can be a slow onset of symptoms. A worsening cough, headaches, and muscle aches may be the only symptoms. At times, the individual's skin color may change and become dusky or purplish due to their blood being poorly oxygenated.
Children and babies often do not have any specific signs of a chest infection, but develop a fever, appear quite ill, and can become lethargic. Elderly people may also have few symptoms with pneumonia.
How is pneumonia diagnosed?
Pneumonia may be suspected when the doctor examines the patient and hears coarse breathing or crackling sounds when listening to a portion of the chest with a stethoscope. There may be wheezing or the sounds of breathing may be faint in a particular area of the chest. A chest x-ray is usually ordered to confirm the diagnosis of pneumonia.
Sputum samples can be collected and examined under the microscope. If the pneumonia is caused by a bacteria, it can often be detected by this examination. A sample of the sputum can be grown in special incubators and the offending bacteria can be subsequently identified. A blood test can be performed (called a CBC) and the white blood cell count of this test can often give a hint as to the severity of the pneumonia and whether it is caused by a bacteria or a virus.
Bronchoscopy is a procedure in which a thin, flexible lighted viewing tube is inserted into the nose or mouth after a local anesthetic is administered. The breathing passages can then be directly examined by the doctor and specimens from the infected part of the lung can be obtained. Sometimes, fluid collects around the lung as a result of the inflammation from pneumonia. This fluid is called a pleural effusion. If the amount of this fluid that develops is large enough, it can be removed by inserting a needle into the chest cavity and withdrawing the fluid with a syringe. This procedure is called a thoracentesis.
What are some of the organisms that cause pneumonia and how are they treated?
The most common cause of a bacterial pneumonia is Streptococcus pneumoniae. There is usually an abrupt onset of the