Pronounced: Noo-MO-NEE-yah
Pneumonia is an infection of the lungs caused by a variety of different organisms.
Effects of Pneumonia on the Lungs

Pneumonia affects the lower respiratory tract (small bronchi and air sacs in the lungs). There are three main causes:
Bacterial Pneumonia— caused by bacteria, most commonly Streptococcus pneumoniae
Viral Pneumonia— caused by a virus. Viruses cause half of all pneumonias.
Atypical Bacterial Pneumonia— caused by mycoplasmas, chlamydias, or other tiny infectious agents that have traits of both bacteria and viruses. Walking pneumonia, as this type of pneumonia is often popularly called, implies a milder pneumonia. However, each of these infectious agents has the potential to cause a more serious or potentially fatal pneumonia.
Other causes of pneumonia include:
• Fungal infections, such as Pneumocystis cariniipneumonia (PCP)—a fungal infection common in people with AIDS
Pneumonias are sometimes divided on the basis of where it was acquired and how you were exposed to it:
• Community Acquired Pneumonia—this type of pneumonia is acquired, as the name suggests, in the community (ie, at school, work, gym etc.)
• Nosocomial Pneumonia—is acquired during a hospitalization. It can be very dangerous, especially for patients on a ventilator.
• Aspiration Pneumonia—it happens when a foreign matter (most frequently stomach content) is inhaled.
Risk Factors
A risk factor is something that increases your chance of getting a disease or condition.
Risk factors include:
• Age: 65 or older
• Flu or other respiratory illness
• Chronic illness, such as heart or lung disease
• Stroke (aspiration pneumonia due to difficult swallowing)
• Weakened immune system caused by AIDS or chemotherapy treatment
• Chronic bronchitis
• Malnutrition
• Pregnancy
• Infants and very young children
• Alcohol or drug abuse
• Smoking
• Chronic exposure to certain chemicals (eg, work in construction or agriculture)
Symptoms of pneumonia may include some or all of the following:
Bacterial Pneumonia Viral Pneumonia Atypical Pneumonia
Fever Fever Fever, often low-grade
Shaking chills Chills Chills
Cough that produces green, yellow, or rust-colored mucus Dry cough Coughing; may be violent at times; produces white mucus
Chest pain Headache Possible nausea or vomiting
Profuse sweating Muscle pain Weakness
Bluish color of the nails or lips due to diminished oxygen in the blood Bluish color of the nails or lips due to diminished oxygen in the blood
Confused mental state Weakness
The doctor will ask about your symptoms and medical history, and perform a physical exam. Diagnosis of pneumonia is based on symptoms and listening to your chest with a stethoscope. In addition, tests may include:
• Chest X-ray —a test that uses radiation to take pictures of structures inside the body, in this case the chest
• CT Scan —a type of x-ray that uses a computer to make pictures of structures inside the chest
• Blood Tests
• Bronchoscopy —direct examination of airways
• Sputum Culture—testing mucus coughed up from deep in the lungs
• Pulse Oximetry—measures the amount of oxygen in the blood
• Arterial Blood Gas—measures oxygen, carbon dioxide, and acid in the blood
Treatment of pneumonia depends on:
• The type of pneumonia
• Severity of symptoms
• Other factors
Common methods of treatment include:
Bacterial Pneumonia
Viral Pneumonia
• Rest and fluids
• Antiviral medicines—may be prescribed for young children and patients with weakened immune systems ( Note: Antibiotics are ineffective for treating viral pneumonia.)
Atypical Pneumonia
Usually treated with antibiotics.
• Over-the-counter medicines to reduce fever and aches, and soothe cough
• Hospitalization, for people with very severe symptoms
It is very important to take medicine exactly as prescribed. Stopping medicine midway may cause a relapse, or create a strain of bacteria resistant to drug treatment.
Certain vaccines can help prevent pneumonia:
Flu Shot— for people at high risk, particularly the elderly, because pneumonia may be a complication of the flu
Pneumococcal Vaccine— recommended for people over age 65, or those who have a chronic illness, such as diabetes or sickle-cell disease
Other preventive measures include:
• Avoid smoking. Smoking weakens the lungs' resistance to infection.
• Avoid close contact with people who have respiratory infections.
• Wash hands often when coming in contact with infected people.
• Protect yourself from exposures on the job that affect the lungs.
• Eat a healthy diet.
• Get adequate rest.
• Exercise regularly.