Pneumonia is a common lung infection caused by bacteria, a virus or fungi. It is often spread via coughing, sneezing, touching or even breathing, and those who don't exhibit symptoms can also spread the illness. What Is Pneumonia?Pneumonia is an infection of the lungs that may be caused by bacteria, viruses, or fungi. The infection causes the lungs' air sacs (alveoli) to become inflamed and fill up with fluid or pus. That can make it hard for the oxygen you breathe in to get into your bloodstream. The symptoms of pneumonia can range from mild to severe, and include cough, fever, chills, and trouble breathing. Many factors affect how serious a case of pneumonia is, such as the type of germ causing the lung infection, the person’s age, and their overall health. The people most at risk are infants and young children, adults 65 or older, and people who have other health problems. Pneumonia is a leading cause of hospitalization in both children and adults. Most cases can be treated successfully, although it can take weeks to fully recover. Tens of thousands of people in the U.S. die from pneumonia every year, most of them adults over the age of 65. What Causes Pneumonia?Pneumonia can be caused by a wide variety of bacteria, viruses and fungi in the air we breathe. Identifying the cause of your pneumonia can be an important step in getting the proper treatment. Learn more about what causes pneumonia. What Are the Risk Factors?Anyone can get pneumonia, but many factors can increase your chances of getting sick and having a more severe illness. One of the most important factors is your age. People age 65 and over are at increased risk because their immune system is becoming less able to fight off infection as years go by. Infants and children two years of age or younger are also at increased risk because their immune systems are not yet fully developed. Other risk factors can be grouped into three main categories: medical conditions, health behaviors, and environment. Medical conditions
Health behaviors
Environment
Next: What Causes Pneumonia?
Pneumonia is an infection in your lungs that inflames the air sacs, sometimes filling them with fluid or pus. It can be caused by a number of different organisms, including bacteria, viruses, and fungi, as well as by aspirating (inhaling) a foreign object. Pneumonia affects millions of people every year, particularly children under age 5 and adults over age 65, as well as people who are hospitalized or who have chronic illnesses or immunosuppression. Symptoms can range from mild to severe and include a productive cough, fever, chills, and difficulty breathing. Pneumonia isn't one single disease, and the cause determines what treatment is needed. Bacterial pneumonia is the most common type of pneumonia and often only affects one area of your lung. It sometimes occurs after you've had some other type of infection that weakens your immune system, like a cold or the flu, but the condition can also occur on its own without a preceding infection.
Bacterial pneumonia is usually treated with antibiotics. Examples of bacteria that can cause bacterial pneumonia include:
Atypical bacteria are bacteria that are unable to be cultured with standard methods. Atypical bacteria that cause pneumonia include:
Viral pneumonia, by definition, is caused by a virus and is the most common cause of pneumonia in children under age 5. It's usually not as serious as bacterial pneumonia, though it puts you at a higher risk of developing it.
Most people with viral pneumonia recover within one to three weeks without treatment, though some cases become severe and require hospitalization. Examples of viruses that can cause viral pneumonia include:
Fungal pneumonia is caused when spores enter your lungs and multiply. It commonly occurs in people with compromised immune systems or chronic health problems. However, it can occur in otherwise healthy adults too. Fungal infections that are picked up from the soil in certain areas of the United States can lead to fungal pneumonia, including:
Aspiration happens when a foreign object, such as a piece of food, gum, liquid, or vomit, is inhaled. The object then becomes lodged in one or both lungs where it's trapped, unless you're able to cough it up. When you aspirate a foreign object or liquid, it increases the presence of bacteria as the object begins to rot, leading to an infection.
Aspiration pneumonia, or the collection of infectious material in the lungs due to the presence of a foreign object, can make it difficult to breathe. Some people may have an ongoing condition where they accidentally swallow food into their lungs instead of into their esophagus, the tube that moves food to the stomach. Many people never even realize that a piece of food has gone down the "wrong pipe." This problem is more common in the elderly, who are more likely to have problems with swallowing. The risk of pneumonia due to aspiration while under anesthesia is also why patients are asked not to eat or drink prior to surgery.
Pneumonia can affect anyone at any age, but the two age groups at the highest risk both for contracting it and for having more severe cases are children under age 2 and adults over age 65. Other risk factors include:
Risk factors that may have to do with your lifestyle choices increase your likelihood of developing pneumonia and include:
It's important to be aware that your risk of pneumonia increases with each additional health or lifestyle risk factor you have. Frequently Asked Questions
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