What Is a Lower Respiratory Infection?

X-ray of lungs
Could you have a lower respiratory infection?. Gary Lowell/E+/Getty Images

Most people have heard the term upper respiratory infection. It is often used interchangeably when describing a respiratory virus or the common cold. But do you know what a lower respiratory infection is? 

Lower respiratory infections are illnesses that affect the respiratory system below the throat. Any infection that affects the lungs and lower airways are considered a lower respiratory infection.


The most common and well-known lower respiratory infections are pneumonia and bronchitis, as well as bronchiolitis in children. 


Pneumonia is an infection of the lungs. There are many types of pneumonia. It can be caused by different types of bacteria, viruses, fungi and even inhaled chemicals or solid objects (such as food). Many cases of pneumonia occur as a complication of an upper respiratory infection such as a cold or the flu. 

Most of the time, people with pneumonia are treated with antibiotics. Other medications may be necessary to help with the symptoms. If your illness is severe or you are at high risk, you may be hospitalized when you have pneumonia. To help reduce your risk of serious illness, get your flu vaccine each year. Older adults should get a pneumonia vaccine as well. 


Bronchitis is irritation and swelling in the airways leading to the lungs. Most often, it is caused by a virus and will go away on its own.

Although coughing can be uncomfortable and last for weeks, antibiotics are rarely helpful for bronchitis since they do not kill viruses. Other treatments may be useful if you have been diagnosed with bronchitis. Your health care provider may prescribe an inhaler to help with a cough and breathing difficulty.

She may also recommend over the counter medications such as pain relievers or expectorants

If you have bronchitis but start to feel worse and run a fever, contact your healthcare provider or seek medical attention. Sometimes secondary bacterial infections develop in people with bronchitis. If this happens, your treatment will be different and antibiotics may be necessary. 


Bronchiolitis is inflammation or swelling of the small airways in the lungs. It is an illness that occurs primarily in children younger than 2 years old. It most commonly occurs in babies between 3 and 6 months old, with ​RSV being the primary cause. 

Wheezing and coughing are the primary symptoms of bronchiolitis. It can be a serious and sometimes fatal illness for young infants. If you notice any of these signs that your child is having difficulty breathing, seek medical attention right away, even if you don't suspect bronchiolitis. It's important to know what to watch for. It's not always obvious when a child is having trouble breathing.

Knowing what to watch for could save a child's life. 

Lower respiratory infections can be dangerous and generally are more serious than upper respiratory infections. Know what to watch for so you can seek medical attention if it's needed. 


"Parainfluenza". Medical Encyclopedia 30 Aug 14. MedlinePlus. US National Library of Medicine. National Institutes of Health. US Department of Health and Human Services. 28 Dec 15. 

"Infection and Incidence". RSV 4 Dec 14. National Center for Immunization and Respiratory Disease, Division of Viral Diseases. US Centers for Disease Control and Prevention. US Department of Health and Human Services. 28 Dec 15. 

"Bronchiolitis". Medical Encyclopedia 22 Aug 13. MedlinePlus. US National Library of Medicine. National Institutes of Health. US Department of Health and Human Services. 28 Dec 15.

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