Imminent lung infections capture the world’s
attention because of the potential for pandemics.
Recent examples include avian influenza and the
severe acute respiratory syndrome (SARS). However,
even in the absence of new pathogens or pandemics,
lung infections have tremendous impact. Lung infections
cause more disease than other threats to the public’s
health such as cancer, heart attacks, strokes,
HIV/AIDS, tuberculosis, or malaria. This persistent
and pervasive burden of lung infections receives
little attention from the biomedical and public
Lung infections are especially common and severe
among the poor populations.
Some bacteria that cause disease can produce
toxic substances that may worsen the disease.
Pseudomonas aeruginosa is a bacteria that can
produce a variety of toxins and is of special
interest for patients with cystic fibrosis and
repeated long term lung infections.
Pneumonia is an Infection of the Lung
Pneumonia is an infection in one or both of
the lungs. Many small germs, such as bacteria,
viruses, and fungi, can cause pneumonia.
The infection causes your lungs’ air
sacs, called alveoli to become inflamed. The
air sacs may fill up with fluid or pus, causing
symptoms such as a cough with phlegm, fever,
chills and trouble breathing.
Pneumonia and its symptoms can vary from mild
to severe. Many factors affect how serious pneumonia
is, such as the type of germ causing the infection
and your age and overall health.
Pneumonia tends to be more serious for:
and young children.
- Older adults . . . people 65 years or older
- People who have other health problems like
heart failure, diabetes, or COPD
- People who have weak immune systems as a result
of diseases or other factors.
Pneumonia is common in the United States.
Treatment for pneumonia depends on its cause,
how severe your symptoms are, and your age and
overall health. Many people can be treated at
home, often with oral antibiotics.
Children usually start to feel better in 1
to 2 days. For adults, it usually takes 2 to
3 days. Anyone whose symptoms get worse should
be checked by a doctor.
People who have more severe symptoms or underlying
health problems may need treatment in a hospital.
It may take 3 weeks or more before they can
go back to their normal routines.
Fatigue from pneumonia can last for a month
Bronchiectasis is a Lung Disease that Starts
from an Infection in the Lungs
Bronchiectasis is a lung disease that usually
results from an infection or other condition
that injures the walls of the airways in your
lungs. The airways are the tubes that carry
air in and out of your lungs.
This injury is the beginning of a cycle in
which your airways slowly lose their ability
to clear out mucus. The mucus builds up and
creates an environment in which bacteria can
grow. This leads to repeated serious lung infections.
Each infection causes more damage to your airways.
Over time, your airways become stretched out,
flabby, and scarred. They can no longer move
air in and out.
This can affect how much oxygen reaches your
body organs. If your lungs cannot move enough
oxygen into your body, bronchiectasis can lead
to serious illness, including heart failure.
Bronchiectasis can affect just one section
of one of your lungs or many sections of both
Bronchiectasis usually begins in childhood,
but symptoms may not appear until months or
even years after you have started having repeated
There are two types of bronchiectasis:
bronchiectasis usually affects infants and
children. It results from a problem in the
development of the lungs in the fetus.
- Acquired bronchiectasis occurs in adults and
older children. It is more common.
Bronchiectasis cannot be cured, but with proper
care, most people who have it can enjoy a good
quality of life.
Bronchitis is a condition in which the bronchial
tubes, the tubes that carry air to your lungs,
People who have bronchitis often have a cough
that brings up mucus. Mucus is a slimy substance
made by the lining of the bronchial tubes. Bronchitis
also may cause wheezing (a whistling or squeaky
sound when you breathe), chest pain or discomfort,
a low fever, and shortness of breath.
There are two main types of bronchitis: acute
which is short term and chronic which is ongoing.
Infections or other factors that irritate
the lungs cause acute bronchitis. The same viruses
that cause colds and the flu often cause acute
bronchitis. These viruses are spread through
the air when people cough. They also are spread
through physical contact (for example, on hands
that have not been washed). Sometimes bacteria
cause acute bronchitis.
Acute bronchitis lasts from a few days to 10
days. However, the cough that occurs may last
for several weeks after the infection is gone.
Several factors increase the risk for acute
bronchitis. Examples include tobacco smoke and
also secondhand smoke, air pollution, dust,
and fumes. Avoiding these lung irritants as
much as possible can help lower your risk for
Most cases of acute bronchitis go away within
a few days. If you think you have acute bronchitis,
see your doctor. He or she will want to rule
out other, more serious health conditions that
need medical care.
Chronic bronchitis is an ongoing, serious
condition. It occurs when the lining of the
bronchial tubes is constantly irritated and
Bronchitis is "chronic" if you have
a cough with mucus on most days for at least
3 months a year and 2 years in a row (without
another apparent cause). Smoking is the main
cause of chronic bronchitis.
Viruses or bacteria can easily infect the irritated
bronchial tubes. When this happens, the condition
worsens and lasts longer. As a result, people
who have chronic bronchitis also have periods
when symptoms get much worse than usual.
Chronic bronchitis is a serious, long-term
medical condition. Early diagnosis and treatment,
combined with quitting cigarette smoking and
avoiding secondhand cigarette smoke, can help
people live better with this condition. The
chance of complete recovery is low for people
who have severe chronic bronchitis.
Pleurisy and Other Disorders of the Pleura
Pleurisy is inflammation of the pleura. The
pleura is a large, thin sheet of tissue that
wraps around the outside of your lungs and lines
the inside of your chest cavity.
Between the layer of the pleura that wraps
around your lungs and the layer that lines your
chest cavity is a very thin space. This is called
the pleural space. Normally it's filled with
a small amount of fluid—about 4 teaspoons
full. The fluid helps the two layers of the
pleura glide smoothly past each other as your
lungs breathe air in and out.
Pleurisy occurs when the two layers of the
pleura become red and inflamed. Then they rub
against each other every time your lungs expand
to breathe in air. This can cause sharp pain
Many different conditions can cause pleurisy.
Viral infection is the most common cause. Other
conditions that can cause pleurisy are:
infections like pneumonia and tuberculosis
- Autoimmune disorders like systemic lupus erythematosus
and rheumatoid arthritis
- Lung cancer, including lymphoma
- Other lung diseases like sarcoidosis, asbestosis,
lymphangioleiomyomatosis, and mesothelioma
- Pulmonary embolism, a blood clot in the blood
vessels that go into the lungs
- Inflammatory bowel disease
- Familial Mediterranean fever, an inherited
condition that often causes fever and swelling
in the abdomen or lung
- Infection from a fungus or parasite
- Heart surgery, especially coronary artery
Other causes of pleurisy include:
- Reactions to certain medicines that can cause
a condition similar to systemic lupus erythematosus.
These medicines include procainamide, hydralazine,
- In some cases, doctors can't find the cause
of the pleurisy.
Infections like pneumonia are the most common
cause of swelling, or inflammation, of the pleura
Other Disorders of the Pleura:
In some cases of pleurisy, excess fluid builds
up in the pleural space. This is called a pleural
effusion. The buildup of fluid usually forces
the two layers of the pleura apart so they don't
rub against each other when you breathe. This
can relieve your pain.
However, a large amount of extra fluid can
push the pleura against your lung until the
lung, or a part of it, collapses. This can make
it hard for you to breathe.
In some cases of pleural effusion, the extra
fluid gets infected and turns into an abscess.
This is called an empyema
You can develop a pleural effusion if you don't
have pleurisy. For example, pneumonia, heart
failure, cancer, or a pulmonary embolism can
lead to a pleural effusion.
Air or gas also can build up in the pleural
space. This is called a pneumothorax. It can result
from acute lung injury or a lung disease like
emphysema. Lung procedures, like surgery, drainage
of fluid with a needle, examination of the lung
from the inside with a light and a camera, or
mechanical ventilation, also can cause it.
The most common symptom is sudden pain in one
side of the lung and shortness of breath. A
pneumothorax also can put pressure on the lung
and cause it to collapse.
If the pneumothorax is small, it may go away
on its own. If it's large, you may need to have
a tube placed through your skin and chest wall
into the pleural space to remove the air.
Blood also can collect in the pleural space.
This is called hemothorax. The most common cause
of hemothorax is injury to the chest from blunt
force or chest or heart surgery. Hemothorax
also can occur in people with lung or pleural
Hemothorax can put pressure on the lung and
force it to collapse. It also can cause shock,
a state in which not enough blood and oxygen
reach important organs in the body.
Outlook for Pleurisy
Pleurisy and other disorders of the pleura
can be serious, depending on what caused the
inflammation in the pleura.
If the condition that caused the pleurisy or
other pleural disorders isn't too serious and
is diagnosed and treated early, you usually
can expect a full recovery.