What is pneumonia?
Pneumonia is an infection in one or both lungs. It can be caused by bacteria, viruses, or fungi. Bacterial pneumonia is the most common type in adults.
Pneumonia causes inflammation in the air sacs in your lungs, which are called alveoli. The alveoli fill with fluid or pus, making it difficult to breathe.
What are the symptoms of pneumonia?
Pneumonia symptoms can be mild to life-threatening. The most common symptoms of pneumonia can include:
Other symptoms can vary according to the cause and severity of the infection, as well as the age and general health of the individual.
Symptoms by cause
Symptoms by age
What are the types and causes of pneumonia?
The major types of pneumonia are classified by the cause of the infection, where the infection was transmitted, and how the infection was acquired.
Types by germ
Pneumonia can be classified according to the organism that caused the infection.
Bacterial pneumonia: The most common cause of bacterial pneumonia is Streptococcus pneumoniae. Chlamydophila pneumonia and Legionella pneumophila can also cause bacterial pneumonia.
Viral pneumonia: Respiratory viruses are often the cause of pneumonia, especially in young children and older people. Viral pneumonia is usually not serious and lasts for a shorter time than bacterial pneumonia.
Mycoplasma pneumonia: Mycoplasma organisms are not viruses or bacteria, but they have traits common to both. Mycoplasmas generally cause mild cases of pneumonia, most often in older children and young adults.
Fungal pneumonia: Fungi from soil or bird droppings can cause pneumonia in people who inhale large amounts of the organisms. They can also cause pneumonia in people with chronic diseases or weakened immune systems.
One kind of fungal pneumonia is called Pneumocystis jirovecii pneumonia (PCP). This condition generally affects people with weakened immune systems, such as those with AIDS. In fact, PCP can be one of the first signs of infection with AIDS.
Is pneumonia contagious?
Most kinds of pneumonia are contagious.
Both viral and bacterial pneumonia can spread to others through inhalation of airborne droplets from a sneeze or cough. But while you can become infected with fungal pneumonia from the environment, it doesn’t spread from person to person.
Who is at risk of pneumonia?
Anyone can get pneumonia, but certain people are at higher risk:
How is pneumonia diagnosed?
Your doctor will start by asking you questions about when your symptoms first appeared and about your medical history. They’ll also give you a physical exam. This will include listening to your lungs with a stethoscope for any abnormal sounds, such as crackling.
Your doctor will also likely order a chest X-ray. Typically, pneumonia can be diagnosed with the physical exam and the chest X-ray. But depending on the severity of your symptoms and your risk of complications, your doctor may also order one or more of these tests:
How is pneumonia treated?
Your treatment will depend on the type of pneumonia you have, how severe it is, and your general health.
Antibiotic, antiviral, and antifungal drugs are used to treat pneumonia, depending on the specific cause of the condition. Most cases of bacterial pneumonia can be treated at home with oral antibiotics, and most people respond to the antibiotics in one to three days.
Your doctor may also recommend cough medicine to calm your cough so you can rest. However, coughing helps remove fluid from your lungs, so you don’t want to eliminate it entirely.
You can help your recovery and prevent a recurrence by:
If your symptoms are very severe or you have other health problems, you may need to be hospitalized. At the hospital, doctors can keep track of your heart rate, temperature, and breathing. Treatment may include:
Worsened chronic conditions
If you have certain health problems already, pneumonia could make them worse. These conditions include congestive heart failure and emphysema.
For certain people, pneumonia increases their risk of having a heart attack.
Pneumonia may cause complications, especially in people with weakened immune systems or chronic diseases such as diabetes. Complications can include: