What Is Pneumonia?

Pneumonia is a lung infection that causes inflammation in the air sacs of the lungs. These air sacs can fill with fluid or pus, making it harder to breathe and get enough oxygen.

Pneumonia may be caused by bacterial infections, viral illnesses such as the flu or COVID-19, or fungal infections. Older adults, young children, smokers, and people with weakened immune systems are at higher risk.

Pneumonia can affect one or both lungs and may range from mild to severe. The infection can be caused by bacteria, viruses, fungi, or inhaled irritants.

Symptoms

Symptoms of pneumonia can develop suddenly or gradually. Some people have mild symptoms, while others become seriously ill and need hospital care.

Common symptoms include:

• Cough with mucus
• Fever or chills
• Shortness of breath
• Chest pain when breathing or coughing
• Fatigue
• Sweating
• Loss of appetite
• Rapid breathing
• Muscle aches or headache

How Is It Diagnosed?

Healthcare providers diagnose pneumonia by reviewing symptoms, listening to the lungs, and checking oxygen levels.

Testing may include:

• Chest X-ray
• Blood tests
• Pulse oximetry
• Sputum testing
• CT scan in some cases

Additional testing may be needed if symptoms are severe or complications are suspected.

How Is It Treated?

Treatment depends on the cause of the infection and how severe the symptoms are. Many people recover at home with rest, fluids, and medication.

Treatment may include:

• Antibiotics for bacterial pneumonia
• Antiviral medicines in some viral cases
• Fever and pain relievers
• Oxygen therapy
• Breathing support for severe illness
• Hospital care when needed

Recovery time varies from person to person. Some people feel better within a few weeks, while others may need longer to regain strength and energy.

Vaccines for influenza and pneumococcal disease can help lower the risk of pneumonia and serious complications.