Pneumonia Health Article

Definition

Pneumonia is an infection of the lungs. Many different organisms can cause it, including bacteria, viruses, and fungi.

Alternative Names

Bronchopneumonia; Community-acquired pneumonia

Causes, incidence, and risk factors

Pneumonia is a common illness that affects millions of people each year in the United States.

Bacterial pneumonias tend to be the most serious and, in adults, the most common cause of pneumonia. The most common pneumonia-causing bacterium in adults is Streptococcus pneumoniae (pneumococcus).

Respiratory viruses are the most common causes of pneumonia in young children, peaking between the ages of 2 and 3. By school age, the bacterium becomes more common.

In some people, particularly the elderly and those who are debilitated, bacterial pneumonia may follow influenza or even a common cold.

Many people contract pneumonia while staying in a hospital for other conditions. This tends to be more serious because the patient's immune system is often impaired due to the condition that initially required treatment. In addition, there is a greater possibility of infection with bacteria that are resistant to antibiotics.

See also:

• Aspiration pneumonia
• Atypical pneumonia
• CMV pneumonia
• Hospital-acquired pneumonia
• Legionella pneumonia
• Pneumonia in immunocompromised host
• Viral pneumonia
• Walking pneumonia

Symptoms

The main symptoms of pneumonia are:

• Cough with greenish or yellow mucus; bloody sputum happens on occasion
• Fever with shaking chills
• Sharp or stabbing chest pain worsened by deep breathing or coughing
• Rapid, shallow breathing
• Shortness of breath

• Headache
• Excessive sweating and clammy skin
• Loss of appetite
• Excessive fatigue
• Confusion , especially in older people

Signs and tests

If you have pneumonia, you may be working hard to breathe, or may be breathing fast. Crackles are heard when listening to your chest with a stethoscope. Other abnormal breathing sounds may also be heard through the stethoscope or via percussion (tapping on your chest wall).

The following tests may show signs of pneumonia:

• Chest x-ray
• Gram's stain and culture of your sputum to look for the organism causing your symptoms
• CBC to check white blood cell count; if high, this suggests bacterial infection
• Arterial blood gases to check how well you are oxygenating your blood
• CAT scan of the chest
• Pleural fluid culture if there is fluid in the space surrounding the lungs

Treatment

If the cause is bacterial, the goal is to cure the infection with antibiotics. If the cause is viral, typical antibiotics will NOT be effective, however sometimes your doctor may use antiviral medication. In some cases it is difficult to distinguish between viral and bacterial pneumonia, so antibiotics may be prescribed.

Many people can be treated at home with antibiotics. If you have an underlying chronic disease, severe symptoms, or low oxygen levels, you will likely require hospitalization for intravenous antibiotics and oxygen therapy. Infants and the elderly are more commonly admitted for treatment of pneumonia.

You can take these steps at home:

• Drink plenty of fluids to help loosen secretions and bring up phlegm.
• Get lots of rest. Have someone else do household chores.
• Control your fever with aspirin or acetaminophen. DO NOT give aspirin to children.

When in the hospital, respiratory treatments to remove secretions may be necessary. Occasionally, steroid medications may be used to reduce wheezing if there is an underlying lung disease.

Expectations (prognosis)

With treatment, most patients will improve within two weeks. Elderly or debilitated patients who fail to respond to treatment may die from respiratory failure.

Complications

Empyema or lung abscesses are infrequent, but serious, complications of pneumonia. They occur when pockets of pus form around or inside the lung. These may sometimes require surgical drainage.