John Carew, MD, is board-certified in otolaryngology-head and neck surgery. He is an adjunct assistant professor at Mount Sinai Medical Center and NYU Medical Center.
Pneumonia is a lung infection that can range from mild to life-threatening. It is commonly caused by bacterial or viral infections but can sometimes be due to fungal infections or aspirating (inhaling) a substance into the lungs. Pneumonia leads to airway inflammation and the alveoli (air sacs) may fill with fluid. Some cases will cause a problem in one lobe (segment) of one lung, while serious cases can affect all five lobes.
Viral pneumonia can be due to flu, respiratory syncytial virus (RSV), or COVID-19. Bacterial pneumonia is often due to Streptococcus pneumoniae and referred to as pneumococcal pneumonia.
Treatments may include prescription or over-the-counter (OTC) medications and breathing treatments. In severe cases, hospitalization may be necessary.
Viruses and certain bacteria that can lead to pneumonia are contagious and infections can occur after coming into contact with someone who is infected or touching contaminated surfaces. Bacterial infections can also occur after the immune system is weakened due to illnesses. Anyone can get pneumonia, but children under age 2 and adults over age 65 have an increased risk of severe infections.
There are four types:
Pneumonia leads to a severe cough in many cases. This is your body's way of trying to clear out sputum (a pus-like mixture of saliva and mucus) that collects in the alveoli of the lungs. It can also cause symptoms such as fever, shortness of breath, chest pain, body aches, vomiting, weakness, and feeling confused.
Treatment varies based on the cause of the infection and severity of symptoms. It may include antibiotics (bacterial pneumonia), antivirals (viral pneumonia), or antifungals (fungal pneumonia). There may also be over-the-counter medications or supplemental oxygen. Plenty of rest and fluids is recommended. Severe cases may require hospitalization and the use of a ventilator, but this is uncommon.
The bacteria Mycoplasma pneumoniae causes an infection commonly referred to as walking pneumonia. It’s called this because it often has mild symptoms and typically responds well to antibiotics. Walking pneumonia is a form of community-acquired pneumonia that spreads in crowded environments, such as dormitories or daycares.
Recovery from pneumonia can range from one week to a month or more. Your doctor may want to see you for follow-up appointments and may do tests, such as chest X-rays to check for fluid in your lungs. If your symptoms start to improve and then get worse, contact your physician. This can be a sign that your infection isn’t responding to medication or that you’ve developed another infection.
Air sacs in the lungs that exchange oxygen and carbon dioxide when you breathe. Pneumonia can cause the alveoli to become inflamed and to fill with fluid. Coughing is a way to expel some of this fluid.
Pneumonia that’s caused by a bacterial infection and usually treated with antibiotics.There is a vaccine to help prevent pneumococcal infections, which are a common cause of bacterial pneumonia.
A test to measure blood oxygen levels. It uses a probe or sensor on places such as the fingertip, forehead, ear, or nose to get a measurement of oxygen saturation within your blood. A normal reading is typically between 95% and 100%. Levels in those with chronic obstructive pulmonary disease (COPD), asthma, lung cancer, heart failure, and pneumonia, may be lower.
A test that examines sputum (phlegm) under a microscope to help diagnose conditions such as bacterial pneumonia or asthma. The sample is commonly collected by having you take deep breaths and then coughing into a cup.
Centers for Disease Control and Prevention. Causes of Pneumonia. Updated October 22, 2020.
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American Lung Association. Pneumonia treatment and recovery. Updated October 23, 2020.