(at-uh-LEK-tuh-sis) — a complete or partial collapse of a lung — is a
possible complication of many respiratory problems. Mucus in the airways
after surgery, cystic fibrosis, inhaled foreign objects, severe asthma
and chest injuries are among the common causes of atelectasis.
Unlike pneumothorax, which is air between the chest wall and lung,
atelectasis develops when the tiny air sacs (alveoli) within the lung
The amount of lung tissue involved in atelectasis is variable, depending
on the cause. Signs and symptoms of atelectasis also vary with the
underlying cause and the extent of lung involvement. Atelectasis can be
serious because it impairs the exchange of oxygen and carbon dioxide in
your lungs. Treatment depends on the cause and severity of the collapse.
Depending on the severity of the atelectasis, there may be no obvious
signs or symptoms. If you do experience signs and symptoms, they may
* Difficulty breathing (dyspnea)
* Rapid, shallow breathing
* Low-grade fever (in a child)
When to see a doctor
Significant atelectasis is likely to occur when you're already in a
hospital. However, see your doctor right away if you have trouble
breathing. Other conditions besides atelectasis can cause breathing
difficulties, and most require an accurate diagnosis and prompt
treatment. If your breathing becomes increasingly difficult, seek
Atelectasis may be the result of a blocked airway (obstructive
atelectasis) or of pressure outside your lung (nonobstructive
atelectasis). To understand how it occurs, think of soap bubbles. Just
as a soap bubble's liquid surface keeps the bubble intact, a surface
agent (surfactant) coats each of the tiny air sacs (alveoli) in your
lungs so they don't collapse. Anything that diminishes surfactant, such
as pressure on the lungs, can cause atelectasis.
A blockage in your air passages (bronchial tubes) can cause obstructive atelectasis. Possible causes of blockage include:
* Mucus plug. Accumulation of mucus in your airways, often occurring
during and after surgery, is the most common cause of atelectasis.
Drugs given during surgery make the lungs inflate less fully than they
ordinarily do, so normal secretions collect in the airways. Suctioning
the lungs during surgery helps clear away these secretions, but they may
continue to build up afterward. This is why it's important to breathe
and cough deeply during your recovery. Expanding the lungs gets air
around the mucus plugs and makes them easier to cough out. Mucus plugs
also are common in people with cystic fibrosis and during severe asthma
* Foreign body. Children are most likely to inhale an object, most commonly a peanut, into their lungs.
* Narrowing of major airways from disease. Tuberculosis and other
diseases that involve the major airways can cause them to narrow.
* Tumor in a major airway. A cancer or a benign growth can narrow the airway.
* Blood clot. This occurs only if there's significant bleeding into the lungs that can't be coughed out.
Pressure on the outside of your lungs can cause nonobstructive atelectasis. Possible causes include:
* Injury. Chest trauma — from a fall or car accident, for example — can damage and compress your lungs.
* Pleural effusion. This is a buildup of fluid between the tissues
(pleura) that line the lung and the inside of the chest wall.
* Pneumonia. Different types of pneumonia, an inflammation of your
lungs, temporarily can cause nonobstructive as well as obstructive
atelectasis. An atelectatic lung that remains collapsed for a few weeks
or more can result in bronchiectasis (brong-ke-EK-tuh-sis), a condition
in which damage to the airways causes them to widen and become flabby
* Pneumothorax. Air leaks into the space between your lungs and
chest wall, indirectly causing some or all of a lung to collapse.
* Scarring of lung tissue. Scarring could be caused by injury, lung
disease or surgery. In these rare cases, the atelectasis is minor
compared with the damage to the lung tissue from the scarring.
* Tumor. Certain large tumors can put pressure on the lung, as opposed to blocking the air passages.
Factors that increase your risk of atelectasis include:
* Premature birth, if the lungs aren't fully developed
* Any condition that interferes with spontaneous coughing, yawning and sighing
* Lung disease, such as asthma, bronchiectasis or cystic fibrosis
* Confinement to bed, with infrequent change of position
* Abdominal or chest surgery
* Recent general anesthesia
* Shallow breathing — a result of abdominal pain or rib fracture, for example
* Respiratory muscle weakness, due to muscular dystrophy, spinal cord injury or another neuromuscular condition
* Obesity, which can elevate your diaphragm and hamper your ability to inhale fully
The following complications may result from atelectasis:
* Low blood oxygen (hypoxemia). Atelectasis hampers your lungs' ability to get oxygen to the alveoli.
* Lung scarring. Some damage or scarring may remain after the lung is reinflated, resulting in bronchiectasis.
* Pneumonia. You're at greater risk of developing pneumonia until the atelectasis has been cleared.
* Respiratory failure. A small area of atelectasis, especially in an
adult, usually is treatable. But a large area, particularly in an
infant or in someone with lung disease, can be life-threatening.
Preparing for your appointment
Unless you require emergency care, you're likely to start by seeing your
family doctor or a general practitioner. However, in some cases when
you call to set up an appointment, you may be referred immediately to a
It's a good idea to prepare for your appointment. Here's some information to help you.
What you can do
* Write down any symptoms you're experiencing, including any that
may seem unrelated to the reason for which you scheduled the
* Make a list of all medications, vitamins or supplements you're
taking. Some medications, such as antihistamines, can make your
secretions thicker and more difficult to cough out.
* Take a family member or friend along, if possible. Sometimes it
can be difficult to soak up all the information you get during an
appointment. Someone who accompanies you may remember something that you
missed or forgot.
* Write down questions to ask your doctor.
Preparing a list of questions for your doctor will help you make the
most of your time together. List your questions from most important to
least important. For atelectasis, some basic questions to ask your
* What is likely causing my symptoms or condition?
* Other than the most likely cause, what are other possible causes for my symptoms or condition?
* What kinds of tests do I need?
* Is my condition likely temporary or chronic?
* What is the best course of action?
* What are the alternatives to the primary approach you're suggesting?
* I have these other health conditions. How can I best manage them together?
* Are there any restrictions that I need to follow?
* Is there a generic alternative to the medicine you're prescribing?
* Are there any brochures or other printed material that I can take home with me? What Web sites do you recommend?
Don't hesitate to ask other questions during your appointment if you don't understand something or need more information.
What to expect from your doctor
Your doctor is likely to ask you a number of questions, including:
* When did you begin experiencing symptoms?
* Have your symptoms been continuous or occasional?
* How severe are your symptoms?
* What, if anything, seems to improve your symptoms?
* What, if anything, appears to worsen your symptoms?
Tests and diagnosis
A chest X-ray usually can diagnose atelectasis. Symptoms of a
respiratory infection, especially pneumonia, on a child's chest X-ray
may indicate a foreign body, the most common cause of obstructive
atelectasis in children.
To determine the underlying cause, your doctor may order other tests, including:
* Computerized tomography (CT) scan. CT is an X-ray technique that
produces more-detailed images than conventional X-rays do. A CT scan can
help determine whether a tumor may have caused your lung to collapse —
something that may not show up on a regular X-ray.
* Oximetry. This simple test uses a small device placed on one of
your fingers to measure the oxygen saturation in your blood.
* Bronchoscopy. A flexible, lighted tube threaded down your throat
enables your doctor to see and possibly remove, at least partially,
obstructions in your airway, such as a mucus plug, tumor or foreign
Treatments and drugs
Treatment of atelectasis depends on the cause. Atelectasis of a small
area of your lung may subside without treatment. If there's an
underlying condition, such as a tumor, treatment may involve removal or
shrinkage of the tumor with surgery, chemotherapy or radiation.
In some cases, medications may be used. They include:
* Acetylcysteine (Acetadote, Mucomyst), which thins mucus and makes it easier to cough up.
* Inhaled bronchodilators (Foradil, Maxair, Proventil, Serevent,
Ventolin, Xopenex), which open the bronchial tubes of the lungs, making
* DNase (Dornase Alfa), which is used to clear mucus plugs in
children with cystic fibrosis and is gaining acceptance as a treatment
for atelectasis for people without cystic fibrosis.
A number of therapies known as chest physiotherapy are used to treat atelectasis. They include:
* Clapping (percussion) on your chest over the collapsed area to loosen mucus
* Performing deep-breathing exercises (incentive spirometry)
* Positioning your body so your head is lower than your chest (called postural drainage), which allows mucus to drain better
* Supplemental oxygen, which can help relieve shortness of breath (dyspnea)
Surgical or other procedures
Your doctor may suggest removal of airway obstructions, which may be
done by suctioning mucus or by bronchoscopy. Bronchoscopy uses a
flexible tube threaded down your throat to clear your airways. Often,
the person performing the procedure (bronchoscopist) can partially
remove a tumor to open the airway and temporarily relieve the
To decrease atelectasis risk:
* Leave out the nuts. Do not give children nuts until they are about
3 years old, when they have molars to more thoroughly chew nuts.
* Stop smoking. Smoking increases mucus production and damages the
small, hair-like structures that line the bronchial tubes (cilia). Their
wave-like motion helps carry mucus out of your airways.
* Do deep-breathing exercises. After surgery, follow your doctor's
instructions for frequent coughing and doing deep-breathing exercises.
* Reposition yourself. If you must stay in bed, change your position frequently. Get up and walk as soon as you're able.