Pneumonia-Diseases (I)

Pneumonia-Diseases (I)
by Robert Baird

Pneumonia is not a specific disease. It is a general term for several kinds of inflammation of the lungs. Pneumonia is usually caused by a bacterial or viral infection, but it can also be caused by chemical damage to the lungs from inhaling a poisonous gas such as chlorine. The pneumonia, or lung inflammation, can be anything from a mild complication of an upper respiratory tract infection to a life- threatening illness.

The symptoms, the treatment, the impact, and the outcome of pneumonia depend on the cause, the general health of the person concerned, and on other factors. Viral pneumonia, for instance, does not respond to treatment with antibiotics. See the accompanying table for a comparison of the causes and likely results of five of the most common types of pneumonia.

The variability of pneumonia has led to many popular and medical descriptive terms. If you are told that you have "double" pneumonia, it means that both your lungs are affected. If your attack is due to bacteria-like microbes called Mycoplasma, you may be said to have "atypical" pneumonia. "Bronchopneumonia" is patchy inflammation of one or both lungs, and "lobar" pneumonia affects the entire area of one or more lobes of the lung. When your physician determines what kind of pneumonia you have, you can ask for a description of that type. What are the symptoms?

No single symptom is characteristic of all types of pneumonia. You should consider the possibility of pneumonia, however, if you already have a respiratory illness with symptoms such as a cough and fever, and you become short of breath while at rest and for no apparent reason. Additional symptoms to watch for besides coughing and a temperature are chills; sweating; chest pains; cyanosis, or a bluish tinge to the skin; blood in the phlegm; and, occasionally, mental confusion or delirium. The larger the lung area that is affected, the more severe the symptoms you experience will be.

How quickly the symptoms begin and which symptoms are most prominent varies with the cause of the infection. An especially virulent strain of the influenza virus can cause a pneumonia that can kill a feeble person within 24 hours. In a healthy young adult, pneumonia resulting from a mild respiratory infection might cause symptoms that are no worse than those of an ordinary cold. What are the risks?

In the United States, about 15 people out of 1,000 have pneumonia each year. The disorder is often the final complication of some other debilitating disorder, and this is why many people who get pneumonia die. Any one whose resistance is already low is very susceptible to pneumonia, so for people who are dying of heart failure, cancer, stroke or chronic bronchitis, the actual cause of death is often pneumonia. In anyone who is semiconscious or paralyzed, infection of the lungs is extremely likely. This is because under such conditions the normal coughing reflex that keeps the lungs clear of mucus and stagnant fluid is reduced, or even absent.

You are also more likely than other people to get pneumonia if you are very young (under 2) or very old (over 75), if you have a chronic chest disease such as asthma or some other chronic illness that reduces your body's resistance to infections, or if you are a heavy smoker or drinker. If you are under longterm treatment with immune or anti-inflammatory drugs, especially steroids, you are also susceptible to pneumonia. These drugs decrease the body's normal defenses against infection.