• Hospital patients, especially those in the intensive care unit (ICU)
• People suffering from chronic diseases such as diabetes, asthma, chronic obstructive pulmonary disease (COPD), and heart disease
• People with compromised immune systems, such as those with HIV/AIDS, organ transplant recipients, cancer patients receiving chemotherapy, or those with a history of prolonged use of immunosuppressive medications    
• Smokers

• Airborne transmission; being coughed on, sneezed on, or breathed on by an infected person. These are ways to get the infection directly into the lungs
• Choking, in which saliva and food bits can bring infection from the upper respiratory tract into the lungs. This is often an issue among older adults and chronic disease sufferers
• Bloodstream infection, for example, contracting the infection from prolonged urinary catheterization or intravenous (IV) administration
• Infection from an abscess near the lungs, for example, a liver abscess

• White Blood Cell (WBC) Count – This can help determine if there is an infection from bacteria or a virus, although the test cannot identify the specific type of infection
• Blood Oxygen Level Test – This measures the ability of the lungs in getting oxygen into the blood
• Sputum and Blood Culture Tests – These tests determine the type of infectious agent

• Coughing with phlegm
• Chest pain while breathing and coughing
• Rapid breathing / difficulty breathing
• Fever, sweating, chills
• Nausea, vomiting
• Fatigue
• Obtundation (altered consciousness) and confusion, fall in body temperature in older adults
• Bloating, aversion to drinking water or milk in very young children

• Antibiotics – For bacterial infections, the doctor will prescribe antibiotics based on the type of bacterial infection, which is determined by cultures and clinical-epidemiological data. It is important to note that prolonged use of antibiotics can increase resistance of certain bacteria, such as Streptococcus pneumoniae.   
• Symptom-based treatment – As symptoms present themselves, the doctor may prescribe fever-reducing medications, bronchodilators, and expectorants. Intravenous fluid and oxygen therapy or chest physical therapy (CPT) may be given in severe cases. 
• Treatment of complications – Bacteria may travel from the lungs into the bloodstream to other organs. Some people may experience pleural effusion (fluid build-up in the space between the lungs and chest wall, which may need drainage) or lung abscesses. In severe cases, patients can experience potentially fatal respiratory failure and require breathing assistance.

Pneumonitis, especially infectious pneumonitis (pneumonia), has the potential of being life-threatening. The following methods can help with pneumonia prevention:

• Getting vaccinated – Doctors recommend that those in high risk groups such as children, adults over 65, and those with compromised immune systems get vaccinated for prevention of pneumonia; vaccines include the influenza and pneumococcal vaccines.

• Pneumococcal Polysaccharide Vaccine (PPV) – This is recommended for high risk persons and older adults; should be taken every 5 years
• Pneumococcal Conjugate Vaccine (PCV)  – This protects against several strains of pneumococci: PCV 7, PCV 10, which are recommended for children 6 weeks to 5 years of age, and PCV 13, which is recommended for those in high risk groups and older adults 

Those in high risk groups can take both the influenza and pneumococcal vaccines during the same appointment, having one shot in each arm. After the vaccination, patients may feel a bit of discomfort at the area where the shot was administered; generally the discomfort usually subsides in 2-3 days. 

• Do not smoke, as tobacco smoke harms the lungs’ natural defense mechanism against infection; avoid being around cigarette smoke, smoke from fires, automobile exhaust, and cold weather
• Practice good hygiene, wash your hands frequently, and try to avoid crowded areas
• If suffering from a cold or flu, get treated quickly and do not let the condition persist
• Strengthen your immune system by getting sufficient sleep, eating healthy foods, and getting regular exercise
• Be aware of the dangers of excessive alcohol consumption, which can lead to aspiration pneumonia, which develops from liquid, food, vomit, or saliva being inhaled into the lungs.