Pneumonia

What is Pneumonia?

What is pneumonia? Pneumonia is an infection in one or both of the lungs. It causes the air sacs of the lungs to fill up with fluid or pus. It can range from mild to severe, depending on the type of germ causing the infection, your age, and your overall health. What causes pneumonia? Bacterial, viral, and fungal infections can cause pneumonia. Bacteria are the most common cause. Bacterial pneumonia can occur on its own. It can also develop after you've had certain viral infections such as a cold or the flu. Several different types of bacteria can cause pneumonia, including: Streptococcus pneumoniae Legionella pneumophila; this pneumonia is often called Legionnaires' disease Mycoplasma pneumoniae Chlamydia pneumoniae Haemophilus influenzae Viruses that infect the respiratory tract may cause pneumonia. Viral pneumonia is often mild and goes away on its own within a few weeks. But sometimes it is serious enough that you need to get treatment in a hospital. If you have viral pneumonia, you are at risk of also getting bacterial pneumonia. The different viruses that can cause pneumonia include: Respiratory syncytial virus (RSV) Some common cold and flu viruses SARS-CoV-2, the virus that causes COVID-19 Fungal pneumonia is more common in people who have chronic health problems or weakened immune systems. Some of the types include: Pneumocystis pneumonia (PCP) Coccidioidomycosis, which causes valley fever Histoplasmosis Cryptococcus Who is at risk for pneumonia? Anyone can get pneumonia, but certain factors can increase your risk: Age; the risk is higher for children who are age 2 and under and adults age 65 and older Exposure to certain chemicals, pollutants, or toxic fumes Lifestyle habits, such as smoking, heavy alcohol use, and malnourishment Being in a hospital, especially if you are in the ICU. Being sedated and/or on a ventilator raises the risk even more. Having a lung disease Having a weakened immune system Have trouble coughing or swallowing, from a stroke or other condition Recently being sick with a cold or the flu What are the symptoms of pneumonia? The symptoms of pneumonia can range from mild to severe and include: Fever Chills Cough, usually with phlegm (a slimy substance from deep in your lungs) Shortness of breath Chest pain when you breathe or cough Nausea and/or vomiting Diarrhea The symptoms can vary for different groups. Newborns and infants may not show any signs of the infection. Others may vomit and have a fever and cough. They might seem sick, with no energy, or be restless. Older adults and people who have serious illnesses or weak immune systems may have fewer and milder symptoms. They may even have a lower than normal temperature. Older adults who have pneumonia sometimes have sudden changes in mental awareness. What other problems can pneumonia cause? Sometimes pneumonia can cause serious complications such as: Bacteremia, which happens when the bacteria move into the bloodstream. It is serious and can lead to septic shock. Lung abscesses, which are collections of pus in cavities of the lungs Pleural disorders, which are conditions that affect the pleura. The pleura is the tissue that covers the outside of the lungs and lines the inside of your chest cavity. Kidney failure Respiratory failure How is pneumonia diagnosed? Sometimes pneumonia can be hard to diagnose. This is because it can cause some of the same symptoms as a cold or the flu. It may take time for you to realize that you have a more serious condition. Your health care provider may use many tools to make a diagnosis: A medical history, which includes asking about your symptoms A physical exam, including listening to your lungs with a stethoscope Various tests, such as A chest x-ray Blood tests such as a complete blood count (CBC) to see if your immune system is actively fighting an infection A Blood culture to find out whether you have a bacterial infection that has spread to your bloodstream If you are in the hospital, have serious symptoms,

Related topics

• COVID-19 (Coronavirus Disease 2019)