How Do You Get Pneumonia?

Pneumonia is frequently caused by bacteria and viruses which can be contagious, depending on the pathogen. Pneumonia is a potentially deadly lung condition that can affect one or both lungs and cause cough, fever, and trouble breathing.

Pneumonia is a type of lung infection that can affect one or both lungs and cause cough, fever, and trouble breathing. Pneumonia may result in serious illness in young children, adults over age 65, and people with other health problems.

What Are Symptoms of Pneumonia?

Symptoms of pneumonia include:

• Cough
• May produce phlegm or mucus that may be greenish, yellow, or bloody
• Difficulty breathing
• Shortness of breath
• Rapid, shallow breathing
• Sharp pain on inhalation or when coughing
• Fever 
• Chills and shaking 
• Fast heartbeat
• Sweating
• Loss of appetite
• Lack of energy
• Fatigue
• Nausea and vomiting, especially in small children
• Confusion, especially in older people

Common causes of pneumonia include bacteria, viruses, and fungi. 

Typical bacteria that cause pneumonia include:

• S. pneumoniae (most common bacterial cause)
• Haemophilus influenzae
• Moraxella catarrhalis
• Staphylococcus aureus
• Group A streptococci
• Aerobic gram-negative bacteria (e.g., Enterobacteriaceae such as Klebsiella spp or Escherichia coli)
• Microaerophilic bacteria and anaerobes (associated with aspiration)

Atypical bacteria that cause pneumonia include:

• Legionella spp
• Mycoplasma pneumoniae
• Chlamydia pneumoniae
• Chlamydia psittaci
• Coxiella burnetii

Respiratory viruses that cause pneumonia include:

• Influenza (“flu”) A and B viruses
• Coronaviruses (e.g., Middle East respiratory syndrome coronavirus, COVID-19)
• Rhinoviruses
• Parainfluenza viruses
• Adenoviruses
• Respiratory syncytial virus
• Human metapneumovirus
• Human bocaviruses

Pneumonia is frequently caused by bacteria and viruses which can be contagious, depending on the pathogen. 

The germs that cause pneumonia can be spread from person-to-person in a number of ways: 

• Respiratory droplets in the air after an infected person coughs or sneezes
• Touching a surface or object that is contaminated with the bacteria or virus and then touching your face
• Sharing personal items such as cups and utensils with an infected person

Bacterial pneumonia is usually considered contagious until you have taken antibiotics for 24 to 48 hours. Viral pneumonia remains contagious as long as symptoms are present. 

Pneumonia is diagnosed with a patient history and physical exam, in which a doctor will check the lungs with a stethoscope to listen for crackling, bubbling, and rumbling sounds on inhalation.

Tests to diagnose pneumonia include: 

• Blood tests 
  • Polymerase chain reaction (PCR)
  • Influenza
• Nasal swab for COVID-19
• Sputum test on a sample of mucus (sputum) taken after a deep cough
• Urinary antigen testing for S. pneumoniae
• Pulse oximetry 
• Chest X-ray 
• Computerized tomography (CT) scan of the chest 
• Arterial blood gas test
• Pleural fluid culture
• Bronchoscopy

Treatment for pneumonia depends on a number of factors: 

• The type of pneumonia
• The severity of the patient’s illness
• The patient’s age
• Other coexisting health conditions

Medications used to treat pneumonia include:

• Antibiotics to treat bacterial pneumonia
• Antivirals to treat viral pneumonia

Home care to relieve symptoms may be all that is needed and may include:

• Rest
• Drinking plenty of fluids, including warm beverages to help open airways
• Fever reducers 
• Aspirin: Adults only. Do not give aspirin to children due to the risk of Reye’s syndrome.
• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Ibuprofen (Advil, Motrin)
• Naproxen (Aleve) 
• Acetaminophen (Tylenol)
• Steamy baths or showers or a humidifier to help open airways 
• Don’t smoke and avoid secondhand smoke 
• Talk to your doctor before you take cough medicines. Coughing helps the body work to get rid of infection and cough supressants may not be indicated for your case

Severe cases of pneumonia may need to be treated in a hospital, and treatment may include:

• Intravenous (IV) fluids
• Intravenous antibiotics
• Oxygen therapy
• Other breathing treatments