Bacterial Pneumonia
Bacterial pneumonia is an infection in one or both lungs. It may involve just one small section of your lung, or it may encompass your entire l...

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What Is Bacterial Pneumonia?

Bacterial pneumonia is an infection in one or both lungs. It may involve just one small section of your lung, or it may encompass your entire lung. The bacteria cause the lung’s air sacs to become inflamed and filled with pus, fluid, and cellular debris. This often impairs the body’s ability to exchange oxygen and carbon dioxide. If you have bacterial pneumonia, you might experience breathlessness or pain as you try to take in oxygen.

Bacterial pneumonia can be mild or serious. It may even lead to respiratory failure or death. The severity of your pneumonia depends on the strength of the bacteria and how quickly you are diagnosed and treated. Your age, health, and immune status are also factors.

Make sure to treat your infection early. Antibiotics can significantly lower your chances of developing more serious complications such as respiratory failure.  

What Causes Bacterial Pneumonia?

There are two kinds of bacterial pneumonia. Doctors classify bacterial pneumonia based on whether you got it outside or inside a hospital. Most people in hospitals are already sick and aren’t as able to fight off a severe infection. Also, the bacteria found in a hospital are usually more dangerous.

Community-Acquired Pneumonia (CAP)

Community-acquired pneumonia (CAP) occurs when you get an infection after exposure to bacterial agents outside of a healthcare setting. This is the most common type of bacterial pneumonia. You can get CAP by breathing in respiratory droplets from coughs or sneezes or by skin-to-skin contact.

A number of bacteria commonly cause CAP:

Streptococcus pneumonia is the leading cause of bacterial pneumonia. It lives in the noses and throats of healthy people. It can enter your lungs through inhalation. It can also enter the bloodstream through a wound or infection within the body. 

Haemophilus influenzae is a bacterium that may live in your upper respiratory tract. It doesn’t usually cause harm or illness unless you have a weakened immune system. It’s the second most common cause of bacterial pneumonia. 

Klebsiella pneumonia resides in the mouth, skin, and digestive tract. It’s a bacterium that’s more prone to infect those with weakened immunity. 

Staphylococcus aureus is a bacterium that more frequently infects drug abusers, patients with chronic illness, or young children. It usually lives on the skin or within the pharynx or intestine.

Hospital-Acquired Pneumonia (HAP)

You get hospital-acquired pneumonia (HAP) within two to three days of exposure to germs in a medical setting, such as a hospital or doctor’s office. This is also called a “nosocomial infection.” This type of pneumonia is often more resistant to antibiotics and more difficult to treat than CAP. Examples of the bacteria that cause HAP include methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa.

Who Is at Risk for Developing Bacterial Pneumonia?

People at higher risk for developing bacterial pneumonia include:

  • infants and children
  • adults over age 65
  • people who are ill or have impaired immunity
  • long-term users of immunosuppressant drugs
  • chronic obstructive pulmonary disease (COPD) patients who use inhaled corticosteroids for long periods of time
  • smokers

What Are the Symptoms of Bacterial Pneumonia?

The most common symptoms of bacterial pneumonia are:

  • a cough with thick yellow, green, or blood-tinged mucus
  • chest pain that worsens when coughing or breathing
  • sudden onset of chills
  • fever of 102°F or above (fever lower than 102°F in older persons)
  • headache
  • muscle pain
  • breathlessness or rapid breathing
  • lethargy or severe fatigue
  • moist, pale skin
  • confusion, especially among older persons
  • loss of appetite

How Is Bacterial Pneumonia Diagnosed?

To diagnose bacterial pneumonia, your doctor will:

  • listen for abnormal chest sounds that indicate a heavy secretion of mucus
  • take a blood sample to determine if your white blood cell count is high, which usually indicates infection
  • take a blood culture, which can help determine if the bacteria has spread to your bloodstream and also help identify the bacterium causing the infection
  • take a sample of mucus, or a sputum culture, to identify the bacterium causing the infection
  • order chest X-rays to confirm the presence and extent of the infection

How Is Bacterial Pneumonia Treated?

Your doctor may prescribe the following medications:

  • an antibiotic that fights the specific bacterium causing your infection
  • a cough medicine to calm the cough and to help you cough up mucus
  • fever medication to reduce your temperature

How Can I Prevent Bacterial Pneumonia?

The Centers for Disease Control and Prevention (CDC) recommends a pneumonia vaccine for adults age 65 and older. The vaccine is also available for adults at higher risk for pneumonia due to impaired health or immune status.

The CDC also recommends the PCV13 pneumonia vaccine for infants and young children. Infants usually receive this vaccine in several doses during their first year. Children may also receive it at other times depending on their vaccine schedule and healthcare needs.

The flu can weaken your immune system. This gives bacteria the perfect opportunity to invade the lungs. An annual flu shot can protect adults against influenza and certain forms of bacterial pneumonia.

You can also reduce your chance of becoming ill by exercising, eating well, avoiding smoking, and getting enough rest. Washing your hands with soap and using sanitizer can help to kill the germs that cause bacterial pneumonia.

Written by: Cynthia Chase and Marijane Leonard
Edited by:
Medically Reviewed by: The Healthline Medical Review Team
Published: Oct 29, 2015
Published By: Healthline Networks, Inc.
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