innerbody

Last Updated: October 25, 2017

Pneumonia

Overview

Pneumonia is a lung infection that causes inflammation of the air sacs (alveoli). This infection is commonly caused by bacteria, viruses, fungi, or mycoplasma. The severity of illness can range from mild to extremely severe.

Picture of lungs with trachea and diaphraghm

Pneumonia is a leading cause of mortality worldwide. The risk of pneumonia is increased in children younger than 2, adults older than 65, people with chronic illnesses, and those with weak immune systems.

Causes and Risk Factors

Pneumonia is classified by the way patients acquire the infection and the specific organisms involved.

Types of Pneumonia

Organisms

Tertiary bronchi within lung

The following organisms most commonly cause pneumonia:

Risk Factors

Pneumonia is more common in people with the following risk factors:

Symptoms and Complications

The most common symptoms of pneumonia include:

Immunocompromised patients and individuals with certain chronic diseases have a higher risk of developing complications with pneumonia, including:

Diagnosis

In patients with pneumonia, a lung examination with a stethoscope may reveal abnormal lung sounds, such as wheezes and crackles. When the symptoms and physical examination suggest pneumonia, X-rays and blood tests may be used to confirm the diagnosis.

Diagnostic Studies

Treatment

Patients may be treated on an outpatient basis or hospitalized. After a patient is diagnosed with pneumonia, the clinician’s decision whether to hospitalize the patient depends on the patient’s age, other medical problems, type of pneumonia, severity of illness, and risk of complications.

Prevention

In cases of HAP and HCAP, the hands of health care personnel often spread the organisms to patients. Hand washing and other good hygiene practices must be performed to prevent pneumonia and other infections. Similarly, medical devices and respiratory equipment should be properly cleaned and disinfected.

The pneumococcal vaccine prevents pneumonia caused by Streptococcus pneumoniae. Vaccinations against influenza (flu) and Haemophilus influenzae type B prevent other forms of pneumonia.

Smokers develop pneumonia more often than nonsmokers. Physicians strongly recommend discontinuation of smoking to lower the risk of pneumonia as well as other related chronic diseases.

Sources

Related Topics

Carla Hightower, MD

Dr. Hightower is an experienced physician who studied medicine at Northwestern University, where she also earned an MBA. As the founder of Living Health Works, she offers health coaching to individuals, private groups and corporations.