Pneumonia is an infection of the lungs. Your lungs have 2 main parts: airways (also called bronchial tubes) and alveoli (also called air sacs). When you breathe, the air moves down through your airways and into your alveoli (say: "al-vee-oh-lie"). From the alveoli, oxygen goes into your blood while carbon dioxide moves out of your blood. When you have pneumonia, your alveoli get inflamed (irritated and swollen) and fill with fluid. This makes it difficult for you to breathe.

Pneumonia is usually caused by bacteria or a virus. It can also be caused by fungi or irritants that you breathe into your lungs.

The following tips can help prevent pneumonia:

Practice good hygiene. Your hands come in contact with many germs throughout the day. You pick them up from surfaces such as doorknobs, other people's hands and your computer keyboard. Take time to wash your hands often, especially after using the restroom and before eating. Use lukewarm water and soap for at least 20 seconds. If soap and water are not available, using an alcohol-based hand sanitizer is the next best thing.

Get the flu vaccine each year. People often develop bacterial pneumonia after a case of the flu. You can reduce this risk by getting the yearly flu shot. The flu shot doesn't protect against all strains of the flu, just the 3 to 4 strains that doctors feel will be most dangerous or widespread in the coming year.

Practice a healthy lifestyle. Eat a balanced diet full of fruits and vegetables. Exercise regularly. Get plenty of sleep. These things help your immune system stay strong.

Don't smoke. Smoking damages your lung's ability to defend against germs that cause pneumonia and other infections.

Avoid sick people. Being around people who are sick increases your risk of catching what they have.

There isn't a vaccine for all types of pneumonia, but 2 vaccines are available. The first is called the pneumococcal conjugate vaccine (PCV). It is recommended for all children younger than 5 years of age. The pneumococcal polysaccharide vaccine (PPSV) is recommended for children 2 years of age and older who are at increased risk for pneumonia (such as children who have weakened immune systems), and for adults who have risk factors for pneumonia. This vaccine is recommended if you:

• Are 65 years of age or older
• Smoke
• Abuse alcohol
• Have certain chronic conditions, such as asthma, diabetes, heart disease or lung disease
• Have cirrhosis
• Have a condition that weakens your immune system, such as the human immunodeficiency virus (HIV), acquired immunodeficiency syndrome (AIDS), kidney failure or a damaged spleen
• Have had your spleen removed for any reason
• Have sickle cell disease
• Have cochlear implants (an electronic device that helps you hear)
• Are taking medicine for a recent organ transplant (these medicines suppress your immune system)
• Are receiving chemotherapy

The pneumococcal vaccines can't prevent all cases of pneumonia. But they can make it less likely that people who are at risk will experience the severe, and possibly life-threatening, complications of pneumonia.

Side effects of PCV are unusual, but can include the following:

• Redness and tenderness at the injection site
• Slight fever
• Irritability
• Loss of appetite

Side effects of PPSV are not common, but can include the following:

• Redness and tenderness at the injection site
• Muscle soreness
• Slight fever

Even if you get the pneumococcal vaccine, you might still develop pneumonia. The symptoms of pneumonia can range from mild to severe, depending on your risk factors. Common symptoms are similar to the symptoms caused by a cold or the flu. They include the following:

• Cough
• Fever
• Bringing up mucus when you cough
• Difficulty breathing
• Chills
• Chest pain

If you have any of these symptoms, or if you suddenly start getting worse after having a cold or the flu, see your family doctor.

Your doctor will diagnose pneumonia based on your medical history and the results from a physical exam. He or she may also need to do some tests, such as a chest X-ray or a blood test.

Treatment depends on the type of pneumonia you have, how severe your symptoms are, how healthy you are overall and your age.

For bacterial pneumonia, your doctor will probably prescribe antibiotics. Most of your symptoms should improve within a few days, although a cough can last for several weeks. Be sure to follow your doctor's directions carefully. Take all the antibiotic medicine that your doctor prescribes. If you don't, some bacteria may stay in your body. This can cause your pneumonia to come back. It can also increase your risk of antibiotic resistance.

Antibiotics don't work to treat viral infections. If you have viral pneumonia, your doctor will likely talk to you about ways to treat your symptoms. Over-the-counter (OTC) medicines are available to lower fever, relieve pain and ease your cough. However, some coughing is okay because it can help clear your lungs. Be sure to talk to your doctor before you take a cough suppressant.

When you have any type of pneumonia, it's important to get lots of rest and drink plenty of fluids.

This information was developed as part of an educational program made possible through support from Wyeth Vaccines.