What is pneumonia?
Pneumonia is a type of lung infection caused by bacteria, viruses, or fungi. It can also be caused by inhalation of certain chemicals that irritate the lung tissue. Pneumonia may affect one or both lungs.
Bacterial pneumonia can develop after a cold or the flu.
Bacterial pneumonia can develop on its own, or after a person has had a cold or the flu. Respiratory diseases or viral infections can put people at greater risk for getting bacterial pneumonia. Risk factors for getting bacterial pneumonia include illless, recent surgery, being immune compromised (such as people with HIV/AIDS or cancer or on certain medications), old age, or malnutrition. When the body's immune system is compromised, bacteria that live in healthy throats can move to the lungs, causing pneumonia and systemic infection.
What is walking pneumonia?
The definition of "walking pneumonia" simply refers to a mild case of pneumonia, where a person is not seriously ill and does not require bed rest or hospitalization. It is usually caused by mycoplasma pneumoniae (M. pneumonia) bacteria. Symptoms are mild, and it most commonly affects school-aged children and young adults under the age of 40.
Pneumonia can be a life-threatening infection.
While many cases of pneumonia can be mild such as with walking pneumonia, left untreated some cases of pneumonia can be serious and even life-threatening. Thousands of people die or are hospitalized from pneumonia each year. Those most at risk of severe infection from pneumonia include smokers, people with heart or lung disease, infants and young children, adults age 65 and older, and people with chronic medical conditions or weakened immune systems. If you have risk factors for severe pneumonia and you develop a cough that won't go away, shortness of breath, chest pain, fever, or you feel worse after recovering from a cold or the flu, see your doctor.
What are symptoms of pneumonia?
Common symptoms of pneumonia include:
- Cough (may produce yellow-green or bloody mucus)
- Fever and chills
- Shortness of breath, sometimes only on exertion
- Chest pain when you cough or inhale deeply
- Sweating and clammy skin
- Loss of appetite
- Confusion (especially in the elderly)
Symptoms of pneumonia may be mild to severe, and can vary depending on your age and health, and what type of pneumonia you have.
Is pneumonia contagious?
This is a tricky question. Technically, pneumonia refers to inflammation of the lungs which in itself is not contagious. However, causes of pneumonia such as bacteria or viruses can be contagious.
Pneumonia-causing bacteria or viruses can be spread from person to person from respiratory droplets in the air, such as when a person coughs or sneezes. These particles can also land on surfaces such as doorknobs or tables, where another person can touch the surface and then their face and become infected. Mycoplasma pneumoniae (M. pneumonia) bacteria that often causes walking pneumonia (mild cases), methicillin-resistant Staphylococcus aureus (MRSA) bacteria, and tuberculosis are all highly contagious. The period in which a person is contagious can range from one or two days to up to two weeks.
If the cause of pneumonia is due to aspiration (inflammation of the lungs that results from inhalation of foreign material, such as food, liquid, saliva, or vomit) it is not contagious.
Pneumonia is one of the top 10 causes of death in the United States.
Combined with influenza, pneumonia is the 8th leading cause of deaths in the United States. According to the Centers for Disease Control (CDC), the leading causes of death are:
1. Heart disease
3. Chronic lower respiratory diseases
4. Accidents (unintentional injuries)
5. Stroke (cerebrovascular diseases)
6. Alzheimer's disease
8. Influenza and Pneumonia
9. Nephritis, nephrotic syndrome, and nephrosis
10. Intentional self-harm (suicide)
There is a vaccine against pneumonia.
There are currently vaccines to prevent two types of pneumonia. These vaccines won't prevent all cases of pneumonia but they can reduce the risk of severe and life-threatening complications.
PCV13 (Prevnar 13) is recommended for all children younger than 5 years old, all adults 65 years or older, and people 6 years or older with certain risk factors.
Pneumococcal polysaccharide vaccine (PPSV23 or Pneumovax) is recommended for children older than 2 years old, and all adults who are 65 years or older who are at high risk for pneumococcal disease. Those at high risk include people who smoke or abuse alcohol, have chronic medical conditions (asthma, diabetes, heart or lung disease, cirrhosis of the liver), weakened immune systerms (HIV/AIDS, kidney failure, damaged or removed spleen), sickle cell disease, are taking medication to prevent organ transplant rejection, or are receiving chemotherapy.
Side effects of pneumonia vaccines are usually mild and temporary, and include injection site reactions (redness, tenderness), low fever, loss of appetite, muscle soreness, or irritability.
Images provided by:
7. Bigstock Photo
American Lung Association. Pneumonia.
Medscape. Bacterial Pneumonia – Pathophysiology.
American Academy of Family Physicians. Pneumonia.
CDC. Mycoplasma pneumoniae Infection
American Lung Association. Pneumonia Symptoms, Causes, and Risk Factors.
New Hampshire Department of Health and Human Services Division of Public Health Services.
CDC. Leading Causes of Death. Deaths: Final Data for 2013, table 10.
CDC. Vaccines and Immunizations. Pneumococcal Vaccination: Who Needs It?
American Academy of Family Physicians. Pneumonia – Prevention.
This tool does not provide medical advice. See additional information:
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional medical advice, diagnosis or treatment and should not be relied on to make decisions about your health. Never ignore professional medical advice in seeking treatment because of something you have read on the MedicineNet Site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
© 1996-2023 MedicineNet, Inc. All rights reserved.