Pneumonia - Symptoms and causes - Mayo Clinic Pneumonia is an infection that inflames the air sacs in one or both lungs The air sacs may fill with fluid or pus (purulent material), causing cough with phlegm or pus, fever, chills, and difficulty breathing A variety of organisms, including bacteria, viruses and fungi, can cause pneumonia
Pneumonia - World Health Organization (WHO) Pneumonia is an infection of the lungs that is most commonly caused by viruses or bacteria These infections are generally spread by direct contact with infected people Pneumonia affects children and families everywhere, but is most prevalent in South Asia and sub - Saharan Africa Pneumonia can be prevented with simple interventions and treated with low-cost, low-tech medication and care
Pneumonia - What You Need to Know - Drugs. com Pneumonia Medically reviewed by Drugs com Last updated on Nov 2, 2025 Care notes Aftercare Ambulatory Discharge Inpatient Español Overview Risks Symptoms Diagnosis Treatment Prevention What is pneumonia? Pneumonia is an infection in your lungs caused by bacteria, viruses, fungi, or parasites You can become infected if you come in contact with someone who is sick You can get pneumonia if
Pneumonitis - Symptoms and causes - Mayo Clinic Pneumonitis is a result of an extra strong defense response by the body's immune system to an irritating substance Common causes of pneumonitis include airborne irritants at a job, in the home or from hobbies Other causes include some cancer treatments and many different medicines Trouble breathing, and often a dry cough, are the most common symptoms of pneumonitis Treatment focuses on