Overview
Pneumonia is an infection in the lungs that causes inflammation and fluid or pus to collect in the air sacs. This can make it harder for oxygen to move into the blood and can lead to coughing, fever, chest pain, and breathing problems. Pneumonia may affect one small area of a lung, a whole lobe, or both lungs.
Key Symptoms
Symptoms often include cough, fever, chills, fast breathing, shortness of breath, and chest pain that may feel worse with deep breaths or coughing. Some people cough up mucus. Older adults may have less typical symptoms, such as confusion, weakness, or a lower-than-usual body temperature. Babies and young children may breathe quickly, feed poorly, seem unusually sleepy, or show signs of struggling to breathe.
Causes and Risk Factors
Pneumonia can be caused by bacteria, viruses, or, less commonly, fungi. It can develop after a cold, influenza, COVID-19, or another infection, or it can happen when germs are breathed into the lungs directly. Risk factors include smoking, chronic lung or heart disease, diabetes, weakened immunity, recent hospitalization, and problems swallowing that raise the chance of food or liquid going into the lungs.
Who Is Affected
Pneumonia can affect people of any age. It is more likely to cause severe illness in infants, adults age 65 and older, pregnant people, and people with long-term medical conditions or weakened immune systems. People living in crowded settings or with limited access to healthcare may also face higher risk of complications.
Prevention
Prevention includes staying up to date on recommended vaccines, including those for influenza, COVID-19, and pneumococcal disease when advised by a healthcare professional. Washing hands, covering coughs, improving indoor air quality, and avoiding tobacco smoke can also help lower risk. Managing chronic health conditions and getting medical care early for worsening respiratory symptoms may reduce complications.
Diagnosis and Tests
A healthcare professional may diagnose pneumonia based on symptoms, a physical exam, and listening to the lungs. Tests can include pulse oximetry to check oxygen levels, chest imaging such as a chest X-ray, and sometimes blood tests or testing of mucus from the lungs. The type of testing depends on age, severity, and whether hospital care is needed.
Treatment Categories
Treatment depends on the cause, severity, age, and overall health of the person. Care may include rest, fluids, oxygen support, and medicines chosen by a clinician based on whether the pneumonia is thought to be bacterial, viral, or fungal. Some people recover at home with close follow-up, while others need hospital care for breathing support and monitoring.
When to Seek Medical Care
Contact a healthcare professional promptly for suspected pneumonia, especially if there is fever with cough, chest pain, fast breathing, or shortness of breath. Infants, older adults, pregnant people, and anyone with chronic illness or a weakened immune system should be assessed early. If symptoms are not improving or are getting worse, medical review is important.
When It May Be an Emergency
Seek urgent or emergency care right away for severe trouble breathing, blue or gray lips or face, chest pain, new confusion, inability to stay awake, signs of very low oxygen, or dehydration with inability to drink. Emergency care is also important for babies who are struggling to breathe, grunting, or having pauses in breathing. Pneumonia can become life-threatening if it causes severe infection or low oxygen levels.