Pneumonia is a serious infection and/or inflammation of your lungs. The air sacs in the lungs fill with pus and other liquid. Oxygen has trouble reaching your blood. If there is too little oxygen in your blood, your body cells can't work properly. Because of this and spreading infection through the body pneumonia can cause death.
The risk of death from pneumonia is higher for people with heart disease, diabetes, or a weakened immune system due to AIDS. You can reduce your risk of problems and death from pneumonia and influenza by getting immunized.
Pneumonia is not a single disease. It can have over 30 different causes. There are five main causes of pneumonia:
- Other infectious agents, such as fungi -- including pneumocystis
- Various chemicals
Pneumonia can be difficult to spot. It often mimics a cold or the flu, beginning with a cough and a fever, so you may not realize you have a more serious condition. Chest pain is a common symptom of many types of pneumonia. Pneumonia symptoms can vary greatly, depending on any underlying conditions you may have and the type of organism causing the infection:
Many types of bacteria can cause pneumonia. Bacterial pneumonia can occur on its own, at the same time as viral pneumonia, or you may develop it after you've had a viral upper respiratory infection such as influenza. Signs and symptoms, which are likely to come on suddenly, include shaking chills, a high fever, sweating, shortness of breath, chest pain, and a cough that produces thick, greenish or yellow phlegm.
Ironically, high-risk groups such as older adults and people with a chronic illness or compromised immune system may have fewer or milder symptoms than less vulnerable people do. And instead of the high fever that often characterizes pneumonia, older adults may even have a lower than normal temperature.
Bacterial pneumonia is often confined to just one area (lobe) of the lung. This is called lobar pneumonia.
About half of pneumonias are caused by viruses. Viral pneumonia tends to begin with flu-like signs and symptoms. It usually starts with a dry (nonproductive) cough, headache, fever, muscle pain and fatigue. As the disease progresses, you may become breathless and develop a cough that produces just small quantities of phlegm that may be clear or white. When you have viral pneumonia, you run the risk of also developing a secondary bacterial pneumonia.
This tiny organism causes signs and symptoms similar to those of other bacterial and viral infections, although symptoms appear more gradually and are often mild and flu-like. You may not be sick enough to stay in bed or to seek medical care and may never even know you've had pneumonia. That's why this type of pneumonia is often called walking pneumonia.
Mycoplasma pneumonia spreads easily in situations where people congregate and is common among schoolchildren and young adults. Mycoplasma pneumonia responds well to treatment with the appropriate antibiotics, although you may continue to have a dry, nagging cough and continue to feel weak during your convalescence.
Certain types of fungus also can cause pneumonia, although these types of pneumonia are much less common. Most people experience few if any symptoms after inhaling these fungi, but some develop symptoms of acute pneumonia, and still others may develop a chronic pneumonia that persists for months.
Pneumonia caused by P. carinii is an opportunistic infection that affects people living with AIDS. People whose immune systems are compromised by organ transplants, chemotherapy, or treatment with corticosteroids or other immune-suppressing drugs such as tumor necrosis factor (TNF) inhibitors also are at risk. The signs and symptoms of Pneumocystis carinii pneumonia include a cough that doesn't go away, fever and shortness of breath.
Your doctor may first suspect pneumonia based on your medical history and a physical exam. During the exam, your doctor will listen to your lungs with a stethoscope to check for abnormal bubbling or crackling sounds (rales) and for rumblings (rhonchi) that signal the presence of thick liquid. Both these sounds may indicate inflammation caused by infection.
You're also likely to have chest X-rays to confirm the presence of pneumonia and to determine the extent and location of the infection. Your doctor can suspect pneumonia, but he or she can't diagnose it without a chest X-ray.
You may also have blood tests to check your white cell count, or to look for the presence of viruses, bacteria or other organisms. Sometimes your doctor may examine a sample of your phlegm or your blood to help identify the microorganism that's causing your illness.
The extent of all this testing depends on how sick you are and your underlying risk factors, and whether or not you're responding to therapy.
If you develop pneumonia, your chances of a fast recovery are greatest under certain conditions: if you're young, if your pneumonia is caught early, if your defenses against disease are working well, if the infection hasn't spread, and if you're not suffering from other illnesses.
In the young and healthy, early treatment with antibiotics can cure bacterial pneumonia, speed recovery from mycoplasma pneumonia, and a certain percentage of rickettsia cases. There is not yet a general treatment for viral pneumonia, although antiviral drugs are used for certain kinds. Most people can be treated at home.
The drugs used to fight pneumonia are determined by the germ causing the pneumonia and the judgment of the doctor. After a patient's temperature returns to normal, medication must be continued according to the doctor's instructions, otherwise the pneumonia may recur. Relapses can be far more serious than the first attack.
Besides antibiotics, patients are given supportive treatment: proper diet and oxygen to increase oxygen in the blood when needed. In some patients, medication to ease chest pain and to provide relief from violent cough may be necessary.
The vigorous young person may lead a normal life within a week of recovery from pneumonia. For the middle-aged, however, weeks may elapse before they regain their accustomed strength, vigor, and feeling of well-being. A person recovering from mycoplasma pneumonia may be weak for an extended period of time.
Adequate rest is important to maintain progress toward full recovery and to avoid relapse. Remember, don't rush recovery!
Because pneumonia is a common complication of influenza (flu), getting a flu shot every fall is good pneumonia prevention.
A vaccine is also available to help fight pneumococcal pneumonia, one type of bacterial pneumonia. Your doctor can help you decide if you, or a member of your family, need the vaccine against pneumococcal pneumonia. It is usually given only to people at high risk of getting the disease and its life-threatening complications.
The greatest risk of pneumococcal pneumonia is usually among people who:
- Have chronic illnesses such as lung disease, heart disease, kidney disorders, sickle cell anemia, or diabetes.
- Are recovering from severe illness
- Are in nursing homes or other chronic care facilities
- Are age 65 or older
If you are at risk, ask your doctor for the vaccine.
Ask your doctor about any revaccination recommendations. The vaccine is not recommended for pregnant women or children under age two.
Since pneumonia often follows ordinary respiratory infections, the most important preventive measure is to be alert to any symptoms of respiratory trouble that linger more than a few days. Good health habits, proper diet and hygiene, rest, regular exercise, etc., increase resistance to all respiratory illnesses. They also help promote fast recovery when illness does occur.