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.
There are 4 types of pneumonia:
The symptoms of pneumonia can range from mild to severe, depending on your risk factors and the type of pneumonia you have. Common symptoms are similar to the symptoms caused by a cold or the flu. They include the following:
You may also sweat, have a headache and feel very tired.
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.
Walking pneumonia is a mild case of pneumonia. It is often caused by a virus or the Mycoplasma pneumoniae bacteria. When you have walking pneumonia, your symptoms may not be as severe or last as long as someone who has a more serious case of pneumonia. You probably won’t need bed rest or to stay in the hospital when you have walking pneumonia.
Pneumonia can be life-threatening if left untreated, especially in people who smoke, have heart disease, or have lung problems, and in adults 65 years of age and older. You should call your doctor if you have a cough that won’t go away, shortness of breath, chest pain and a fever. You should also call your doctor if you suddenly begin to feel worse after having a cold or the flu.
You are more at risk of developing pneumonia if:
You are older than 65 years of age. As you get older, your immune system becomes less able to fight off infections like pneumonia. Babies and young children are also at increased risk because their immune systems are not yet fully developed.
You have a disease or condition that weakens your immune system. When your immune system is weakened, it’s easier for you to get pneumonia because your body can’t fight off the infection. People who have weakened immune systems are also more likely to develop pneumonia from bacteria, viruses and germs that don’t cause pneumonia in healthy people.
People who have any of the following are at increased risk:
People who have recently had an organ transplant and people who are receiving chemotherapy are also at increased risk.
You work in construction or agriculture. Working in environments where you breathe in dust, chemicals, air pollution or toxic fumes can damage your lungs and make them more vulnerable to infections like pneumonia.
You smoke or abuse alcohol. Smoking damages the tiny hairs in the lungs that help remove germs and bacteria. Alcohol abuse can put you at increased risk of aspiration pneumonia, a type of pneumonia that develops after you inhale particles into your lungs. This occurs most often when you vomit and small particles enter your lungs because you are not strong enough to cough the particles out. Alcohol abuse also interferes with the way your white blood cells (which are responsible for fighting infection) work.
You are hospitalized, especially in an intensive care unit (ICU). Pneumonia that you catch in a hospital (called hospital-acquired pneumonia) can be more serious than other types of pneumonia. Your risk increases if you are using a ventilator to help you breathe. Ventilators make it hard for you to cough and can trap germs that cause infection in your lungs.
You have recently had major surgery or a serious injury. Recovering from major surgery or a serious injury often makes you weak. It can also make it difficult for you to cough, which is the body’s quickest defense for getting particles out of the lungs. Recovery also typically requires a lot of bed rest. Lying down on your back for an extended period of time can allow fluid or mucus to gather in your lungs, giving bacteria a place to grow.
You are of Native Alaskan or Native American descent. For reasons unknown to doctors, people of these ethnic groups are at increased risk for pneumonia.
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. A chest X-ray can show your doctor if you have pneumonia and how widespread the infection is. Blood and mucus tests can help your doctor tell whether bacteria, a virus or a fungal organism is causing your pneumonia.
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.
If a fungus is causing your pneumonia, your doctor may prescribe an antifungal medicine.
If your case of pneumonia is severe, you may need to be hospitalized. If you are experiencing shortness of breath, you may be given oxygen to help your breathing. You might also receive antibiotics intravenously (through an IV). People who have weakened immune systems, heart disease or lung conditions, and people who were already very sick before developing pneumonia are most likely to be hospitalized. Babies, young children and adults who are 65 years of age and older are also at increased risk.
In addition to taking any antibiotics and/or medicine your doctor prescribes, you should also do the following:
Your doctor may schedule a follow-up appointment after he or she diagnoses you with pneumonia. At this visit, your doctor might take another chest X-ray to make sure the pneumonia infection is clearing up. Keep in mind that chest X-rays can take months to return to normal. However, if your symptoms are not improving, your doctor may decide to try another form of treatment.
Although you may be feeling better, it’s important to keep your follow-up appointment, especially if you smoke. The infection can still be in your lungs even if you’re no longer experiencing symptoms.
Severe cases of pneumonia may require treatment in the hospital. Your doctor may give you oxygen to help you breathe or antibiotics through an IV.
Complications of pneumonia include pleural effusion and bacteria in the bloodstream. Pleural effusion is when fluid builds up in the layers of tissue between your lungs and the wall of your chest and becomes infected. This can make breathing very difficult. To drain the fluid, a tube may need to be placed between your lungs and your chest wall, or you may need surgery.
Bacteria in the bloodstream occur when the pneumonia infection in your lungs spreads to your blood. This increases the risk that the infection will spread to other organs in your body. Bacteria in the bloodstream are treated with antibiotics.
People who have heart or lung problems, people who smoke, and people who are 65 years of age and older are more likely to experience complications from pneumonia.
You can help prevent pneumonia by doing the following:
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.
Get the pneumococcal vaccine. (See below for more information about the vaccine.)
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.
Don't smoke. Smoking damages your lungs and makes it harder for your body to defend itself from germs and disease. If you smoke, talk to your family doctor about quitting as soon as possible.
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.
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:
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:
Side effects of PPSV are not common, but can include the following:
This information was developed as part of an educational program made possible through support from Wyeth Vaccines.
Written by familydoctor.org editorial staff