Viral vs. Bacterial Pneumonia: What's the Difference?

Pneumonia is an infection of one or both lungs caused by bacteria, a virus, or a fungus. It causes inflammation and fluid build-up in the air sacs, or alveoli, of the lungs. Bacterial and viral pneumonia have similar symptoms but different causes and treatments.

Understanding the difference between bacterial and viral pneumonia can help you get a diagnosis faster and determine what treatments you receive. Read on to learn how to tell the difference between bacterial and viral pneumonia.

What Causes Pneumonia?

Pneumonia is most often caused by a bacteria or virus. In rarer cases, a fungal infection can cause pneumonia. See a healthcare provider to learn what is causing your pneumonia so you can receive proper treatment.

Viral Pneumonia Causes

As its name suggests, viral pneumonia is caused by a virus. Common viruses that can cause pneumonia include:

• Common cold (rhinovirus)
• Influenza
• Respiratory syncytial virus (RSV), which is the most common cause of pneumonia in young children
• SARS-CoV-2

Viral pneumonia is spread through infected respiratory droplets and can be extremely contagious.

Bacterial Pneumonia Causes

Different types of bacteria can cause bacterial pneumonia. The most common cause of bacterial pneumonia is a bacteria called Streptococcus pneumonia. Anyone can get pneumonia this way, but people with weakened immune systems may be at risk.

"If you are not healthy or have problems with your immune system or have conditions that make it harder to fight off bacteria, then you are more susceptible to these bacteria, and it can lead to pneumonia" Roger Lovell, MD, infectious disease specialist, told Health.

Bacterial pneumonia can be spread through contact with infected respiratory droplets, like those found in saliva and mucus.

Symptoms

Bacterial and viral pneumonia have several similar symptoms. “It can be difficult to tell by symptoms alone whether you have viral or bacterial pneumonia,” Kimberly Brown, MD, MPH, an emergency medicine doctor in Memphis, Tenn., told Health.

However, bacterial pneumonia tends to have more severe symptoms that can come on gradually or suddenly. Viral pneumonia symptoms tend to develop over a few days after coming in contact with the virus.

If you experience pneumonia symptoms, it's important to see a healthcare provider before they become severe. Here's how bacterial and viral pneumonia symptoms compare.

How To Tell Which Type of Pneumonia You Have

You'll need to see a healthcare provider to determine which type of pneumonia you have. Still, pneumonia can be difficult to diagnose because its symptoms are similar to those of the flu, common cold, and bronchitis.

To diagnose pneumonia, your healthcare provider will perform a physical exam, focusing on listening to your lungs with a stethoscope, and take in your medical history. If they suspect pneumonia, they'll perform diagnostic tests, possibly including:

• Blood tests: These can determine if your body is fighting an infection.
• Chest X-ray: This can detect inflammation in your lungs.
• Pulse oximetry: This can measure the amount of oxygen in your blood. Low levels of oxygen in your blood can be a sign of pneumonia.
• Sputum test: This is when a sample of mucus is taken to try to detect germs or bacteria.

Other tests that may be ordered to diagnose pneumonia include:

• Arterial blood test: This uses an artery, usually in your wrist, to measure the amount of oxygen in your blood. It is more accurate than pulse oximetry.
• Bronchoscopy: This procedure is performed if you're hospitalized and doctors need to examine your lung airways more closely to possibly detect a blockage or take a fluid or lung tissue sample.
• CT scan: This gives doctors a closer look at your lungs to possibly detect complications or abscesses on the lungs.
  

Treatments

Treatment for pneumonia depends on its cause, the severity of your symptoms, your age, and if you have any health conditions. If you have bacterial pneumonia, your healthcare provider will prescribe an antibiotic. You'll usually begin to feel better within one to three days of taking the antibiotic, but make sure you complete the full course.

Antibiotics cannot treat viral pneumonia. If you have viral pneumonia, you may be prescribed an antiviral medication. Treatments are focused on symptom management.

Common treatments for pneumonia symptom management include:

• Drinking lots of fluid (especially warm liquids) to stay hydrated and possibly break up mucus and phlegm
• Getting plenty of rest
• Taking aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, or acetaminophen (do not give to children), to help get your fever under control
• Taking steam showers to help break up mucus and phlegm
• Trying to avoid smoke or air pollutants to give your lungs time to heal
• Using a humidifier to help break up mucus and phlegm

If your pneumonia symptoms are severe, you may have to go to the hospital for intravenous (IV) fluids and medication, or oxygen therapy.

A Quick Review

Pneumonia is an infection of the lungs that causes inflammation and fluid build-up. Bacteria, viruses, and, in rare cases, fungi can cause pneumonia. Understanding the difference between bacterial and viral pneumonia can help you get a proper diagnosis and determine which treatment you need.

Bacterial and viral pneumonia have similar symptoms, including chest pain, cough, and shortness of breath. However, bacterial pneumonia tends to come on quickly and have more severe symptoms. See a healthcare provider if you experience pneumonia symptoms to get a correct diagnosis.